Fermented feed for increasing the content of omega-3 in broiler chickens and a method for preparing the same

Abstract

This invention belongs to the field of feed technology and provides a fermented feed for increasing the Omega-3 content of broilers and its preparation method. The invention uses soybean protein isolate and maltodextrin to prepare a covalently conjugated wall material to encapsulate the Omega-3 oil phase into microcapsules via Maillard reaction. A dual-protection design, involving low-temperature mixing of this microcapsule with a fermentation matrix, achieves controllable particle size (median particle size 12-27 μm), long-term oxidative stability with a surface oil content of 0.8-1.8 wt% and a peroxide value of 0.5-3.5 meq / kg, as well as resistance to abrasion under mixed storage and transportation machinery and effective release performance during digestion. This invention solves the technical contradictions of existing unsaturated oil microcapsule systems in high-solids processing, high oil-carrying stability, and application coupling performance, and has significant application value in increasing the Omega-3 content of broiler muscle and improving the nutritional quality of poultry meat.

Description

Technical Field

[0001] This invention relates to the field of feed technology, specifically to a fermented feed for increasing the Omega-3 content in broilers and its preparation method. Background Technology

[0002] Omega-3 polyunsaturated fatty acids, as core functional components for improving the nutritional quality of poultry meat, are increasingly in demand in modern broiler farming. Increasing the Omega-3 content in broiler muscle tissue through feed can not only significantly improve the nutritional value and market competitiveness of poultry products but also meet consumers' growing demand for healthy foods. However, due to their highly unsaturated molecular structure, Omega-3 fatty acids are highly susceptible to oxidative degradation during feed processing, storage, transportation, and animal digestion and absorption, leading to loss of bioactivity and accumulation of potentially toxic products. Microencapsulation technology, as an effective means of protecting unsaturated oils, can create physical barriers to isolate pro-oxidative factors such as oxygen and metal ions, and achieve controlled or targeted release within the animal's digestive tract, thus establishing a balance between Omega-3 stability and bioavailability. Therefore, developing an Omega-3 microencapsulation delivery system suitable for feed applications, possessing both high oil-carrying capacity and long-term oxidative stability, is of great significance for increasing the Omega-3 content in broiler muscle, expanding the application scope of functional feed products, and promoting the nutritional upgrading of the poultry industry.

[0003] Current research on the application of Omega-3 microcapsules in feed mainly focuses on the selection of wall materials and optimization of encapsulation processes, but many technical bottlenecks still exist in practical applications. For example, Chinese patent CN101850229B discloses an electrophoretic microcapsule and preparation method of carboxylated butadiene nitrile / gelatin and gum arabic coagulation, but gelatin is prone to thermal denaturation during high-temperature granulation, leading to a decrease in shell strength, and the pH and temperature control window of the coagulation process is extremely narrow, making it difficult to achieve continuous industrial production. Similarly, Chinese patent CN120694385A discloses a high-load starch-based stable noni enzyme spray-dried microcapsule and its preparation method, but the modified starch has limited emulsifying ability and is difficult to form a stable emulsion at high oil loading ratios (oil phase exceeding 40%), resulting in high surface oil content and accelerated oxidation reactions. In addition, although traditional polysaccharide wall materials such as maltodextrin are low in cost and have good film-forming properties, they mainly rely on physical adsorption to bind with the oil phase interface. They are prone to cracking and oil leakage under the mechanical shearing of feed mixing, pelleting and animal digestion. Furthermore, they lack a controllable release mechanism for digestive enzymes, which leads to the premature release and oxidation of Omega-3 in gastric acid, reducing intestinal absorption efficiency and muscle deposition effect.

[0004] Furthermore, previous studies have reported the microencapsulation of DHA or algal oil using a soy protein isolate / maltodextrin system, and the Maillard reaction products of soy protein isolate and maltodextrin are known to improve emulsion stability. However, these technologies primarily focus on microcapsule formation itself and have not yet systematically addressed the challenges of balancing the emulsification-homogenization operating window and particle size control under high oil loading ratios, the influence of the wall material reaction degree on the coupling between shell mechanical strength and controllable release during digestion, and the system integration design issues when microcapsules are used in conjunction with fermentation substrates at low temperatures. Summary of the Invention

[0005] The purpose of this invention is to provide a fermented feed for increasing the Omega-3 content of broilers and its preparation method, which solves the problems of unsaturated oil microcapsule systems in the current processing conditions, such as the difficulty in balancing the operability window and particle size control of the emulsification-homogenization process under high solid content processing conditions, the difficulty in achieving long-term oxidative stability with low surface oil and low peroxide value under high oil loading requirements, and the coupling contradiction of maintaining the microcapsule shell's resistance to wear and wall breakage while maintaining effective release and utilization during animal digestion when added at low temperature and subjected to mixing and transportation mechanical action. The above technical contradictions are difficult to solve simultaneously in systems that only use protein-polysaccharide physical mixed wall materials, in systems with insufficient Maillard reaction, and in systems with excessive reaction.

[0006] To address the aforementioned technical challenges, this invention employs a synergistic strategy combining covalently conjugated wall materials, microcapsule encapsulation, and fermentation matrix carriers. A glycoprotein conjugate wall material with emulsifying, film-forming, and antioxidant capabilities is constructed via Maillard reaction. This material encapsulates an Omega-3 oil phase containing a compound antioxidant to form low-surface-oil microcapsules, which are then mixed with the fermentation matrix at low temperatures. The porous structure and low water activity provide synergistic protection, achieving Omega-3 stability throughout its entire lifecycle.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] A fermented feed for increasing Omega-3 content in broilers, comprising, by weight:

[0009] 75–97 parts by weight of fermentation substrate;

[0010] 3–25 parts by weight of Omega-3 fatty acid microcapsule powder;

[0011] The sum of the mass parts of the fermentation substrate and the Omega-3 fatty acid microcapsule powder is 100 parts by mass;

[0012] The Omega-3 fatty acid microcapsule powder comprises an Omega-3 oil phase and a covalently bonded wall material;

[0013] The covalently bonded wall material is a glycoprotein conjugate obtained by Maillard reaction of soy protein isolate and maltodextrin;

[0014] The mass ratio of the Omega-3 oil phase to the covalently bonded wall material is 35:65 to 60:40;

[0015] The median particle size D50 of the Omega-3 fatty acid microcapsule powder is 12–27 μm, and the surface oil content is 0.8–1.8 wt%, wherein the surface oil content is calculated based on the mass of the Omega-3 fatty acid microcapsule powder; the peroxide value is 0.5–3.5 meq / kg, wherein the peroxide value is calculated based on the mass of the oil phase extracted from the Omega-3 fatty acid microcapsule powder.

[0016] Furthermore, the covalently bonded wall material is prepared through the following steps:

[0017] A1. Raw material preparation: Mix 110–180 parts by weight of soy protein isolate with 80–190 parts by weight of maltodextrin, and add deionized water to make the water content of the mixture 6–10 wt%.

[0018] A2. Covalent combination reaction: Place the mixture obtained in step A1 in a sealed container and react at 65–78°C for 10–22 h;

[0019] A3. Endpoint criterion: The reaction is stopped when the free amino content of the reaction product decreases by 10–23% relative to the mixture obtained in step A1;

[0020] A4. Post-processing: The reaction product is crushed and passed through a 70-95 mesh sieve to obtain the covalently bonded wall material.

[0021] Furthermore, the Omega-3 fatty acid microcapsule powder is prepared through the following steps:

[0022] B1. Oil phase premix: Flaxseed oil and herring oil are mixed to obtain a mixed oil; α-tocopherol and ascorbyl palmitate are added based on the mass of the mixed oil, and the mixture is stirred and mixed at 35–58°C for 20–55 min to obtain an oil phase premix.

[0023] B2. Aqueous phase preparation: The covalently bonded wall material is dispersed in deionized water and stirred at 30–55°C for 20–50 min to obtain an aqueous phase of wall material with a mass fraction of 10–23 wt%.

[0024] B3. Emulsification: The oil phase premix obtained in step B1 is added to the water phase of the wall material obtained in step B2. The mass ratio of the mixed oil in the oil phase premix to the covalently bonded wall material calculated on a dry basis is controlled to be 35:65 to 60:40. Emulsification is carried out by high-speed shearing at a speed of 8000–18000 r / min and an emulsification time of 3–9 min to obtain the emulsion product.

[0025] B4. Homogenization: Homogenize the emulsion product obtained in step B3 at 30–55 MPa 1–3 times to obtain an emulsion;

[0026] B5. Drying: The emulsion obtained in step B4 is spray-dried at an inlet air temperature of 160–185°C and an outlet air temperature of 75–88°C to obtain Omega-3 fatty acid microcapsule powder with a water content of 3–6 wt% and a surface oil content of 0.8–1.8 wt%.

[0027] Furthermore, the fermentation substrate is prepared through the following steps:

[0028] C1. Raw material preparation: Mix 45–68 parts by weight of corn flour or corn grits, 17–32 parts by weight of soybean meal, 6–16 parts by weight of flaxseed meal, and 0–2.5 parts by weight of molasses, and add water to make the moisture content of the mixture 29–37 wt%.

[0029] C2. Sealed fermentation: Lactic acid bacteria are inoculated into the mixture obtained in step C1. The lactic acid bacteria are selected from Lactobacillus plantarum, Lactobacillus acidophilus, or a combination thereof. The inoculation amount is 2 × 10⁻⁶. 6 –8×10 7 CFU / g, and then sealed and fermented at 31–36.5℃ for 60–90 h, with the pH of the material at the end of fermentation being 4.0–4.8;

[0030] C3. Drying: The fermentation product is dried at 45–58°C to a moisture content of 6–12 wt% by hot air drying or belt drying to obtain the fermentation substrate.

[0031] Furthermore, the Omega-3 fatty acid microcapsule powder is added and mixed when the temperature of the fermentation substrate does not exceed 38°C, and the resulting fermented feed has a moisture content of 6–12 wt%.

[0032] Furthermore, in step B1, the mass ratio of the flaxseed oil to the herring oil is 15:85 to 70:30.

[0033] Further, in step B1, based on the mass of the mixed oil, 0.06–0.18 wt% of α-tocopherol and 0.05–0.18 wt% of ascorbate palmitate are added, and the mass ratio of α-tocopherol to ascorbate palmitate is 1:2.3 to 3:1, wherein the ascorbate palmitate is L-ascorbic acid-6-palmitate.

[0034] As a concept of this invention, the design of encapsulating the Omega-3 oil phase with a covalently conjugated wall material is mainly used to enhance the oxidative stability, mechanical strength, and controllable release performance of the microcapsules. Soy protein isolate, as a high-quality plant protein, contains abundant hydrophobic and hydrophilic amino acid residues, which can form a dense protein film at the oil-water interface, effectively reducing the surface tension of oil droplets and preventing oil phase aggregation. Maltodextrin, as a low-DE hydrolyzed starch, has good film-forming properties and low hygroscopicity, and can form a robust glassy matrix after drying. Through the Maillard reaction, lysine, arginine, and other amino acid residues in soy protein isolate undergo covalent condensation with the carbonyl group at the reducing end of maltodextrin, forming a glycoprotein conjugate. This conjugate combines the interfacial activity of proteins with the structural stability of polysaccharides, significantly improving the emulsifying ability and film-forming strength of the wall material. The browning products such as melanoidins generated in the Maillard reaction have natural antioxidant activity, capable of scavenging free radicals and chelating pro-oxidative metal ions, further delaying the oxidation process of Omega-3 fatty acids. It is particularly important to note that the aforementioned improvement effect has a clear critical dependence on the degree of Maillard reaction, which is the key difference between this invention and existing research on soy protein isolate-maltodextrin conjugates. When the free amino content decreases by less than 10%, the covalent bond density between the protein and polysaccharide is insufficient, and the wall material structure behavior is still mainly physical adsorption. The emulsifying ability, film-forming strength, and abrasion resistance are not fundamentally different from those of a simple physical mixture of soy protein isolate and maltodextrin. It only possesses the name of "Maillard conjugate" but cannot achieve the expected performance improvement. When the free amino content decreases by more than 23%, the reaction enters the advanced Maillard stage, the protein molecules undergo excessive cross-linking, the three-dimensional network of the wall material becomes too dense, and proteases and amylases in the digestive tract have difficulty effectively cleaving peptide bonds and glycosidic bonds. The cumulative release rate in in vitro simulated digestion experiments decreases significantly, and the intestinal-targeted release and bioavailability of Omega-3 fatty acids are impaired. This invention defines the degree of reaction within a precise window of 10–23% reduction in free amino content, and is a systematic optimization targeting the criticalities in the above two directions. This quantitative reaction window, designed for feed applications and simultaneously considering the coupling of microcapsule shell mechanical strength and controllable digestible release, lacks corresponding quantitative characterization in existing technical reports on soy protein isolate-maltodextrin M-Grard conjugates. It is a key process criterion independently established by this invention through systematic comparative experiments. The oil phase to wall material mass ratio is controlled within the range of 35:65 to 60:40, ensuring both high oil loading to meet feed additive economics and sufficient wall material thickness for effective encapsulation and oxidative protection. The median particle size of the microcapsules is controlled within the range of 12-27 μm. This particle size range ensures good flowability and mixing uniformity while avoiding excessively small particle sizes leading to excessively large specific surface area and accelerated oxidation rates, as well as excessively large particle sizes resulting in insufficient digestible release.The surface oil content is controlled below 0.8–1.8 wt%, ensuring the physical stability of the powder and low oxidation risk; the peroxide value is controlled at a low level of 0.5–3.5 meq / kg, ensuring the bioactivity and nutritional value of Omega-3 fatty acids.

[0035] This invention also discloses a method for preparing fermented feed that increases the Omega-3 content of broilers, comprising the following steps:

[0036] D1. Preparation of fermentation substrate;

[0037] D2. Preparation of Omega-3 fatty acid microcapsule powder;

[0038] D3. Mixing: When the temperature of the fermentation substrate does not exceed 38°C, the Omega-3 fatty acid microcapsule powder is added to the fermentation substrate and mixed to obtain the fermented feed.

[0039] Furthermore, the fermentation substrate is dried by hot air drying or belt drying.

[0040] Furthermore, the moisture content of the fermented feed is 6–12 wt%.

[0041] As another aspect of this invention, the design of using a fermentation substrate as a carrier for Omega-3 fatty acid microcapsule powder primarily aims to enhance feed nutritional value, improve palatability, and further delay Omega-3 oxidation. The fermentation substrate uses corn, soybean meal, and flaxseed meal as raw materials. Through sealed fermentation with lactic acid bacteria, large-molecule proteins and polysaccharides are degraded into small peptides, free amino acids, and oligosaccharides, significantly improving digestibility and palatability. During fermentation, the lactic acid produced by the lactic acid bacteria lowers the pH to a slightly acidic level of 4.0-4.8, effectively inhibiting harmful microorganisms such as molds and E. coli, and extending shelf life. The bacteriocins and organic acids produced by the lactic acid bacteria have antibacterial and immunomodulatory effects, improving intestinal health and production performance. Flaxseed meal is rich in α-linolenic acid, which, together with the microcapsule-encapsulated herring oil (rich in EPA and DHA), forms a synergistic supplement of plant- and animal-derived Omega-3, comprehensively meeting the nutritional needs of broilers for different types of Omega-3. After fermentation, the microcapsule powder is dried to a low water activity state with a moisture content of 6–12 wt%, inhibiting the activity of lipoxygenase and lipoxygenase and reducing the auto-oxidation rate of Omega-3. The microcapsule powder is added and mixed when the fermentation substrate temperature is ≤38℃ to avoid thermal damage to the microcapsule shell and thermal oxidation of Omega-3, ensuring uniform dispersion. This facilitates secondary protection of the microcapsules by utilizing the porous structure and low water activity of the fermentation substrate, further enhancing the antioxidant stability of the system mechanistically. The synergy of this dual-protection system is reflected in the independence and complementarity of the two mechanisms in the spatial dimension: the protection of the covalently conjugated shell of the microcapsule acts as a chemical barrier to prevent direct contact between the oil core and external pro-oxidative factors, mainly acting on the internal interface layer of the microcapsule particles, throughout the entire process from spray drying to animal digestion and release; the porous carrier protection of the fermentation substrate provides external protection for the particles through physical anchoring and a low water activity environment, mainly acting on the macroscopic dispersion state and storage and transportation stability of the microcapsule particles in the finished feed system. The two mechanisms act on two spatial levels: the interior of the particle and the external environment. Their irreplaceability is confirmed by systematic comparative experiments: In the example using a complete combination of covalently conjugated microcapsules and fermentation substrate, the long-term retention rate of Omega-3 was not only higher than that of the control group whose wall material did not undergo sufficient Maillard reaction, but also higher than that of the control group whose covalently conjugated microcapsules were retained but whose substrate was not fermented. This indicates that the low water activity and porous anchoring provided by the fermentation substrate make an independent contribution to the protection of the microcapsules. The role of the covalently conjugated wall material cannot be replaced by a single component wall material. Both are indispensable and work together to form the systematic innovative basis of the "covalently conjugated microcapsules + fermentation substrate + low temperature post-addition" combination scheme of this invention, further enhancing the antioxidant stability of the system from a mechanistic perspective.

[0042] The synergistic effect of covalently conjugated wall material and Omega-3 oil phase in the microcapsule system of this invention is manifested in three aspects: interface structure construction, improved oxidative stability, and controllable release after digestion. At the interface structure level, after the soybean protein isolate is glycosylated by Maillard reaction, the hydrophobic amino acid residues are oriented at the oil-water interface to form a dense adsorption layer, and the covalently conjugated maltodextrin segments extend into the aqueous phase to form a hydrophilic shell, constructing a "protein core-polysaccharide shell" bilayer interface structure. Compared with a single wall material, this structure has lower interfacial tension and higher steric hindrance stability, and can stably embed up to 60% of the oil phase during high-speed shearing and high-pressure homogenization, while controlling the median particle size within a narrow distribution range of 12-27 μm. In terms of oxidative stability, antioxidants such as melanoidins and reductones from the Maillard reaction products are distributed in the wall material matrix, rapidly scavenging free radicals generated by the auto-oxidation of oils and blocking chain reactions. The dense network of the covalently bonded wall material reduces the rate of oxygen diffusion to the oil core, and the synergistic effect of physical oxygen barrier and chemical antioxidants keeps the peroxide value stable at a low level of 0.5-3.5 meq / kg for a long time. In terms of digestible and controllable release, the peptide bonds and glycosidic bonds in the covalently bonded wall material respond to digestive tract proteases and amylases. In the weakly acidic environment of the stomach, the shell remains intact to prevent premature release of Omega-3, while in the neutral to slightly alkaline environment of the small intestine, it is gradually degraded and released by enzymes, achieving targeted intestinal absorption and high bioavailability, providing more precise digestive responsiveness and higher Omega-3 deposition efficiency in muscle tissue.

[0043] Animal feeding trials showed that the embodiment using a complete combination of covalently conjugated microcapsules and fermentation substrate significantly increased the total n-3 PUFA content in pectoral muscle compared to the control embodiment using only a single-component wall material. This indicates that the mechanical strength and digestive response imparted by the covalently conjugated wall material, combined with the external protection provided by the fermentation substrate, jointly promoted the effective deposition of Omega-3 throughout the entire process of mixing, storage, transportation, and animal digestion.

[0044] Beneficial technical effects

[0045] 1. Significantly improves Omega-3 encapsulation stability and long-term oxidation inhibition: The covalently conjugated wall material constructed by the Maillard reaction of soy protein isolate and maltodextrin forms a composite interface structure that combines the excellent emulsifying properties of proteins, the efficient film-forming properties of polysaccharides, and the natural antioxidant activity of Maillard reaction products. Under high oil loading conditions with an oil phase to wall material mass ratio of 35:65 to 60:40, the median particle size can still be stably controlled within a narrow distribution range of 12-27μm, the surface oil content is reduced to 0.8-1.8wt%, and the peroxide value is maintained at a low level of 0.5-3.5meq / kg for a long time. This effectively solves the technical bottlenecks of traditional physically mixed wall materials that are prone to high surface oil content, fast oxidation rate, and uneven particle size distribution under high oil loading ratios, providing a reliable guarantee for the stability of Omega-3 throughout its entire life cycle of feed processing, storage, transportation, and use.

[0046] 2. Achieving a precise balance between the mechanical strength of the microcapsule shell and its digestible and controllable release: The dense network structure formed by the covalently bonded protein and polysaccharide in the covalently conjugated wall material endows the microcapsule shell with excellent wear resistance. Under the mechanical action of feed mixing, transportation, storage, and animal consumption, the shell can maintain its integrity, avoiding oil leakage and accelerated oxidation. At the same time, the peptide bonds and glycosidic bonds in the wall material can respond to proteases and amylases in the broiler's digestive tract. In the weakly acidic environment of the stomach, the shell is kept stable to prevent premature release and oxidation of Omega-3. In the neutral to slightly alkaline environment of the small intestine, it is gradually enzymatically hydrolyzed to achieve targeted release, which significantly improves the absorption efficiency of Omega-3 in the small intestine and the deposition level in muscle tissue. This solves the technical contradiction that traditional wall materials cannot simultaneously achieve both physical strength and biological responsiveness.

[0047] 3. Synergistic Effect of Fermentation Substrate and Microcapsules on Enhancing the Overall Nutritional Value of Feed: The fermentation substrate, prepared by lactic acid bacteria fermentation using corn, soybean meal, and flaxseed meal as raw materials, significantly improves the digestibility and palatability of feed by degrading macromolecular proteins and polysaccharides to generate small peptides, free amino acids, and oligosaccharides. The lactic acid produced during fermentation lowers the pH to a slightly acidic level of 4.0-4.8, effectively inhibiting the growth of harmful microorganisms and improving intestinal health. The α-linolenic acid rich in flaxseed meal and the EPA and DHA rich in herring oil encapsulated in microcapsules form a full-spectrum synergistic supplement of plant- and animal-derived Omega-3. The fermentation substrate is dried to a low water activity state with a water content of 6-12 wt%, inhibiting lipoxygenase activity and working in conjunction with the oxygen barrier / antioxidant effect of the covalently conjugated shell of the microcapsules to construct a dual protection system for Omega-3.

[0048] 4. Strong process controllability and suitability for continuous industrial production: The Maillard reaction is carried out within a controllable temperature range of 65-78℃ and an adjustable time range of 10-22h, with a 10-23% reduction in free amino content as a clear endpoint criterion. This avoids the stringent requirements of traditional complex coagulation processes, which have extremely narrow pH and temperature windows. The upper and lower limits of this criterion have independent mechanistic basis: below 10%, the degree of covalent conjugation is insufficient, and the emulsification, film strength, and abrasion resistance of the wall material are not essentially different from those of physical mixing of soy protein isolate and maltodextrin, making effective encapsulation impossible; above 23%, excessive cross-linking leads to reduced accessibility to digestive tract proteases and amylases, impaired cumulative release rate during in vitro digestion, and decreased targeted release efficiency of Omega-3 in the intestine. This quantitative reaction degree window, which takes into account both the mechanical strength of feed mixing and transportation and the coupling of animal digestive tract response and release, is a key process parameter that has not been quantitatively defined for feed application scenarios in existing reports on soy protein isolate-maltodextrin Maillard conjugate technologies, and has been independently established by this invention through systematic comparative verification.

[0049] 5. Providing a stable delivery basis for improving Omega-3 deposition in broiler tissues: The fermented feed of this invention can be added to broiler compound feed as a functional supplement. Through multiple mechanisms such as efficient protection by microcapsules, the role of fermentation matrix as a carrier, and targeted release during digestion, Omega-3 fatty acids maintain high stability during feed processing, storage, transportation, and simulated digestion. Combined with the results of low surface oil, low peroxide value, long accelerated oxidation induction period, and a cumulative release rate of 79.5–88.2% in 210 min of in vitro simulated digestion in the examples, it can be reasonably expected that it will be beneficial to the effective release and absorption of Omega-3 fatty acids in the small intestine of broilers, thereby providing a formulation basis for the effective deposition of Omega-3 polyunsaturated fatty acids such as EPA, DHA, and α-linolenic acid in muscle tissue, and helping to improve the nutritional value and functionality of meat products. Attached Figure Description

[0050] Figure 1 The image shows a comparison of FTIR Maillard covalently bonded and physically hybrid wall materials in Example 1 and Comparative Example 5.

[0051] Figure 2 The graph shows the change in the chemical state of XPS N1s as a function of the degree of reaction for Examples 1, 5, and 6.

[0052] Figure 3 The graph shows the changes in the chemical state of C1s carbon in XPS for Examples 1, 5, and 6.

[0053] Figure 4 The main evidence plots are the laser particle size differential distribution curves for Example 1 and Comparative Example 8.

[0054] Figure 5 The image shows the melting peak suppression and encapsulation integrity of the heating curves obtained from DSC temperature scanning of Example 1 and Comparative Example 3.

[0055] Figure 6 The image shows the suppression of crystallization peaks in the cooling curves obtained from DSC cooling scans of Example 1 and Comparative Example 3.

[0056] Figure 7 The graph shows the cumulative release rate over time in simulated in vitro digestion for Examples 1, 6, and 7.

[0057] Figure 8 This is a macroscopic optical photograph of the Omega-3 fatty acid microcapsule powder (obtained by spray drying) from Example 1.

[0058] Figure 9 The image shows the scanning electron microscope (SEM) morphology of the Omega-3 fatty acid microcapsule powder from Example 1. Detailed Implementation

[0059] 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 with reference to the accompanying drawings.

[0060] Example 1

[0061] This embodiment prepares a fermented feed to increase the Omega-3 content of broilers, comprising 85 parts by weight of fermentation substrate and 15 parts by weight of Omega-3 fatty acid microcapsule powder.

[0062] I. Preparation of Covalently Conjugated Wall Materials

[0063] A1. Raw material preparation: Mix 150 parts by weight of soy protein isolate and 125 parts by weight of maltodextrin evenly, and add deionized water to make the water content of the mixture 8.5 wt%.

[0064] A2. Covalent combination reaction: Place the mixture obtained in step A1 in a sealed container and react at 70°C for 14 hours.

[0065] A3. Endpoint criterion: The free amino content was determined by the o-phthalaldehyde method. The reaction was stopped when the free amino content of the reaction product decreased by 15% relative to the mixture obtained in step A1.

[0066] A4. Post-processing: The reaction product of this embodiment is crushed and passed through an 80-mesh sieve to obtain the covalently bonded wall material of this embodiment.

[0067] II. Preparation of Omega-3 fatty acid microcapsule powder

[0068] B1. Oil Phase Premix: Flaxseed oil and herring oil were mixed at a mass ratio of 50:50 to obtain a mixed oil. Based on the mass of the mixed oil in this embodiment, 0.10 wt% of DL-α-tocopherol (potency 500 IU / g) and 0.10 wt% of L-ascorbic acid-6-palmitate (content of 40.3 wt% based on vitamin C) were added, and the mixture was stirred and mixed at 45°C for 35 min to obtain an oil phase premix. In this embodiment, the mass ratio of α-tocopherol to ascorbic acid palmitate was 1:1.

[0069] B2. Aqueous phase preparation: The covalently bonded wall material of this embodiment is dispersed in deionized water and stirred at 40°C for 35 min to obtain a wall material aqueous phase with a mass fraction of 15 wt%.

[0070] B3. Emulsification: The oil phase premix obtained in step B1 is added to the water phase of the wall material obtained in step B2. The mass ratio of the mixed oil in the oil phase premix to the covalently bonded wall material of this embodiment, calculated on a dry basis, is controlled to be 50:50. Emulsification is carried out by high-speed shearing at a speed of 12,500 r / min and an emulsification time of 5 min to obtain the emulsion product.

[0071] B4. Homogenization: The emulsion obtained in step B3 is homogenized twice at 40 MPa to obtain an emulsion.

[0072] B5. Drying: The emulsion obtained in step B4 was spray-dried at an inlet air temperature of 170°C and an outlet air temperature of 80°C. Drying was stopped under the above spray-drying conditions. The resulting powder had a water content of 5 wt% and a surface oil content of 1.0 wt% (determined by Soxhlet extraction with petroleum ether at an extraction temperature of 60°C for 4 hours), thus obtaining the Omega-3 fatty acid microcapsule powder of this embodiment. The median particle size D50 of the Omega-3 fatty acid microcapsule powder of this embodiment was 17 μm (determined by a laser particle size analyzer, with anhydrous ethanol as the dispersion medium; the sample was added to the dispersion medium and shaken for 5 min before measurement), and the peroxide value was 2.5 meq / kg (determined according to GB5009.227-2023, calculated based on the mass of the oil phase extracted from the Omega-3 fatty acid microcapsule powder of this embodiment).

[0073] III. Preparation of Fermentation Substrate

[0074] C1. Raw material preparation: Mix 55 parts by weight of corn flour, 27 parts by weight of soybean meal, 12 parts by weight of flaxseed meal, and 1.5 parts by weight of molasses, and add water to make the moisture content of the mixture 34 wt%.

[0075] C2. Sealed fermentation: Inoculate the mixture obtained in step C1 with commercially available feed-grade Lactobacillus plantarum at a rate of 5 × 10⁻⁶. 6 The concentration was CFU / g, and then the mixture was sealed and fermented at 34℃ for 72 hours. The pH value of the material at the end of the fermentation was 4.5.

[0076] C3. Drying: The fermentation product of this embodiment is dried at 50°C to a water content of 8wt% by hot air drying to obtain the fermentation substrate of this embodiment.

[0077] IV. Preparation of Fermented Feed

[0078] When the temperature of the fermentation substrate in this embodiment drops to 35°C, 15 parts by weight of the Omega-3 fatty acid microcapsule powder in this embodiment are added to 85 parts by weight of the fermentation substrate in this embodiment and mixed thoroughly to obtain the fermented feed of this embodiment. The moisture content of the fermented feed obtained in this embodiment is 8 wt%.

[0079] Features of Example 1: This example employs a balanced formulation design, with a fermentation substrate to microcapsule powder mass ratio of 85:15. The Omega-3 oil phase contains an equal proportion of flaxseed oil and herring oil, ensuring adequate supply of α-linolenic acid (ALA) and docosahexaenoic acid (DHA). The covalently conjugated wall material contains a soy protein isolate to maltodextrin mass ratio of 150:125. The Maillard reaction is carried out at 70°C for 14 hours, resulting in a 15% reduction in free amino content and the formation of moderately cross-linked glycoprotein conjugates. The median particle size of the microcapsule powder is 17 μm, with a surface oil content controlled at 1.0 wt% and a peroxide value of 2.5 meq / kg, demonstrating good encapsulation efficiency and oxidative stability. The fermentation substrate uses a reasonable combination of corn flour, soybean meal, and flaxseed meal, inoculated with 5 × 10⁶ commercially available feed-grade Lactobacillus plantarum. 6 CFU / g, fermented at 34℃ for 72 hours to pH 4.5, ensuring sufficient lactic acid fermentation and nutrient conversion. The process parameters in this embodiment are within the medium range, exhibiting high process stability and good reproducibility, making it suitable for large-scale production. Application Scenarios: The fermented feed of this embodiment is suitable as a functional supplement added to broiler compound feed to stably supplement Omega-3 fatty acids, thereby increasing the Omega-3 fatty acid content in broiler products and improving the nutritional value of meat. It is particularly suitable for the production of high-quality broiler and functional poultry products.

[0080] Example 2

[0081] This embodiment prepares a fermented feed to increase the Omega-3 content of broilers, comprising 75 parts by weight of fermentation substrate and 25 parts by weight of Omega-3 fatty acid microcapsule powder.

[0082] I. Preparation of Covalently Conjugated Wall Materials

[0083] A1. Raw material preparation: Mix 130 parts by weight of soy protein isolate and 170 parts by weight of maltodextrin evenly, and add deionized water to make the water content of the mixture 7 wt%.

[0084] A2. Covalent combination reaction: The mixture obtained in step A1 was placed in a sealed container and reacted at 75°C for 18 hours.

[0085] A3. Endpoint criterion: The free amino content was determined by the trinitrobenzenesulfonic acid method. The reaction was stopped when the free amino content of the reaction product decreased by 20% relative to the mixture obtained in step A1.

[0086] A4. Post-processing: The reaction product of this embodiment is crushed and passed through a 90-mesh sieve to obtain the covalently bonded wall material of this embodiment.

[0087] II. Preparation of Omega-3 fatty acid microcapsule powder

[0088] B1. Oil Phase Premix: Flaxseed oil and herring oil were mixed at a mass ratio of 30:70 to obtain a mixed oil. Based on the mass of the mixed oil in this embodiment, 0.15wt% of DL-α-tocopherol (potency 500 IU / g) and 0.05wt% of L-ascorbic acid-6-palmitate (content of 40.3wt% based on vitamin C) were added, and the mixture was stirred at 55°C for 50 min to obtain an oil phase premix. In this embodiment, the mass ratio of α-tocopherol to ascorbic acid palmitate was 3:1.

[0089] B2. Aqueous phase preparation: The covalently bonded wall material of this embodiment is dispersed in deionized water and stirred at 50°C for 45 min to obtain a wall material aqueous phase with a mass fraction of 20 wt%.

[0090] B3. Emulsification: The oil phase premix obtained in step B1 is added to the water phase of the wall material obtained in step B2. The mass ratio of the mixed oil in the oil phase premix to the covalently bonded wall material of this embodiment, calculated on a dry basis, is controlled to be 60:40. Emulsification is carried out by high-speed shearing at a speed of 16,000 r / min for 7 min to obtain the emulsion product.

[0091] B4. Homogenization: The emulsion obtained in step B3 is homogenized three times at 50 MPa to obtain an emulsion.

[0092] B5. Drying: The emulsion obtained in step B4 was spray-dried at an inlet air temperature of 180°C and an outlet air temperature of 85°C. The resulting powder had a water content of 4 wt% and a surface oil content of 0.8 wt% (determined by Soxhlet extraction with petroleum ether at 60°C for 4 hours), thus obtaining the Omega-3 fatty acid microcapsule powder of this embodiment. The median particle size D50 of the Omega-3 fatty acid microcapsule powder of this embodiment was 12 μm (determined by a laser particle size analyzer, with anhydrous ethanol as the dispersion medium; the sample was added to the dispersion medium and shaken for 5 min before measurement), and the peroxide value was 1.5 meq / kg (determined according to GB5009.227-2023, calculated based on the mass of the oil phase extracted from the Omega-3 fatty acid microcapsule powder of this embodiment).

[0093] III. Preparation of Fermentation Substrate

[0094] C1. Raw material preparation: Mix 45 parts by weight of corn flour, 32 parts by weight of soybean meal, 16 parts by weight of flaxseed meal, and 2.5 parts by weight of molasses, and add water to make the moisture content of the mixture 37 wt%.

[0095] C2. Sealed fermentation: Inoculate the mixture obtained in step C1 with a combination of commercially available feed-grade Lactobacillus plantarum and Lactobacillus acidophilus (mass ratio 1:1), with an inoculation amount of 3 × 10⁻⁶. 7 The concentration was CFU / g, and then the mixture was sealed and fermented at 36℃ for 84 hours. At the end of the fermentation, the pH value of the material was 4.2.

[0096] C3. Drying: The fermentation product of this embodiment is dried at 55°C to a moisture content of 6wt% by a belt dryer to obtain the fermentation substrate of this embodiment.

[0097] IV. Preparation of Fermented Feed

[0098] When the temperature of the fermentation substrate in this embodiment drops to 30°C, 25 parts by weight of the Omega-3 fatty acid microcapsule powder in this embodiment are added to 75 parts by weight of the fermentation substrate in this embodiment and mixed thoroughly to obtain the fermented feed of this embodiment. The moisture content of the fermented feed obtained in this embodiment is 6 wt%.

[0099] Example 2 Features: This example employs a high Omega-3 content formulation strategy, with microcapsule powder added at 25 parts by weight, significantly increasing the Omega-3 fatty acid loading in the feed. The oil phase formulation contains 70% herring oil, rich in long-chain Omega-3 fatty acids such as DHA and EPA, meeting the specific needs of broilers for marine-derived Omega-3. The covalently conjugated wall material has a high proportion of maltodextrin (170 parts by weight), which, after reacting at 75°C for 18 hours, reduces the free amino content by 20%, forming a highly cross-linked glycoprotein network structure, providing excellent encapsulation protection. The antioxidant formulation has a high α-tocopherol content (0.15 wt%), with a mass ratio of 3:1 to ascorbate palmitate, enhancing the fat-soluble antioxidant capacity. The microcapsule powder has a small median particle size (12 μm), a surface oil content of only 0.8 wt%, and a peroxide value as low as 1.5 meq / kg, demonstrating excellent microencapsulation quality. The fermentation substrate contained a high proportion of soybean meal and flaxseed meal, and the inoculum size of the compound lactic acid bacteria was 3×10⁻⁶. 7 CFU / g, fermented at 36℃ for 84 hours to pH 4.2, fully releases bioactive peptides and free amino acids, synergistically enhancing the nutritional value of the feed. This example mainly illustrates the feasibility of the formulation and process under conditions of higher microencapsulated powder addition, and the performance of the microencapsulated powder shown in Table 1.

[0100] Example 3

[0101] This embodiment prepares a fermented feed to increase the Omega-3 content of broilers, comprising 94 parts by weight of fermentation substrate and 6 parts by weight of Omega-3 fatty acid microcapsule powder.

[0102] I. Preparation of Covalently Conjugated Wall Materials

[0103] A1. Raw material preparation: Mix 180 parts by weight of soy protein isolate with 80 parts by weight of maltodextrin evenly, and add deionized water to make the water content of the mixture 10 wt%.

[0104] A2. Covalent combination reaction: The mixture obtained in step A1 was placed in a sealed container and reacted at 65°C for 10 h.

[0105] A3. Endpoint criterion: The free amino content was determined by the o-phthalaldehyde method. The reaction was stopped when the free amino content of the reaction product decreased by 10% relative to the mixture obtained in step A1.

[0106] A4. Post-processing: The reaction product of this embodiment is crushed and passed through a 70-mesh sieve to obtain the covalently bonded wall material of this embodiment.

[0107] II. Preparation of Omega-3 fatty acid microcapsule powder

[0108] B1. Oil Phase Premix: Flaxseed oil and herring oil were mixed at a mass ratio of 70:30 to obtain a mixed oil. Based on the mass of the mixed oil in this embodiment, 0.06 wt% of DL-α-tocopherol (potency 500 IU / g) and 0.14 wt% of L-ascorbic acid-6-palmitate (content of 40.3 wt% based on vitamin C) were added, and the mixture was stirred and mixed at 35°C for 20 min to obtain an oil phase premix. In this embodiment, the mass ratio of α-tocopherol to ascorbic acid palmitate was 1:2.3.

[0109] B2. Aqueous phase preparation: The covalently bonded wall material of this embodiment is dispersed in deionized water and stirred at 30°C for 20 min to obtain a wall material aqueous phase with a mass fraction of 10 wt%.

[0110] B3. Emulsification: The oil phase premix obtained in step B1 is added to the water phase of the wall material obtained in step B2. The mass ratio of the mixed oil in the oil phase premix to the covalently bonded wall material of this embodiment, calculated on a dry basis, is controlled to be 40:60. Emulsification is carried out by high-speed shearing at a speed of 8,000 r / min for 3 min to obtain the emulsion product.

[0111] B4. Homogenization: The emulsion obtained in step B3 is homogenized once at 30 MPa to obtain an emulsion.

[0112] B5. Drying: The emulsion obtained in step B4 was spray-dried at an inlet air temperature of 160°C and an outlet air temperature of 75°C. The resulting powder had a water content of 6 wt% and a surface oil content of 1.5 wt% (determined by Soxhlet extraction with petroleum ether at 60°C for 4 hours), thus obtaining the Omega-3 fatty acid microcapsule powder of this embodiment. The median particle size D50 of the Omega-3 fatty acid microcapsule powder of this embodiment was 22 μm (determined by a laser particle size analyzer, with anhydrous ethanol as the dispersion medium; the sample was added to the dispersion medium and shaken for 5 min before measurement), and the peroxide value was 3.5 meq / kg (determined according to GB5009.227-2023, calculated based on the mass of the oil phase extracted from the Omega-3 fatty acid microcapsule powder of this embodiment).

[0113] III. Preparation of Fermentation Substrate

[0114] C1. Raw material preparation: Mix 62 parts by weight of corn flour, 20 parts by weight of soybean meal, 8 parts by weight of flaxseed meal, and 0.5 parts by weight of molasses, and add water to make the moisture content of the mixture 30 wt%.

[0115] C2. Sealed fermentation: Inoculate the mixture obtained in step C1 with commercially available feed-grade Lactobacillus plantarum at a rate of 2 × 10⁻⁶. 6 The concentration was CFU / g, and then the mixture was sealed and fermented at 31℃ for 60 hours. At the end of the fermentation, the pH value of the material was 4.8.

[0116] C3. Drying: The fermentation product of this embodiment is dried at 45°C by hot air drying until the water content is 10wt% to obtain the fermentation substrate of this embodiment.

[0117] IV. Preparation of Fermented Feed

[0118] When the temperature of the fermentation substrate in this embodiment drops to 38°C, 6 parts by weight of the Omega-3 fatty acid microcapsule powder in this embodiment are added to 94 parts by weight of the fermentation substrate in this embodiment and mixed thoroughly to obtain the fermented feed of this embodiment. The moisture content of the fermented feed obtained in this embodiment is 10 wt%.

[0119] Example 3 Features: This example employs a high-proportion fermentation substrate formulation, with the fermentation substrate accounting for 94 parts by weight, highlighting the probiotic function and nutritional conversion characteristics of the fermented feed. The microcapsule powder is added at 6 parts by weight, providing basic Omega-3 nutritional supplementation. The oil phase formulation contains 70% flaxseed oil, rich in plant-derived α-linolenic acid, suitable for broiler conversion and utilization. The covalently conjugated wall material has a high proportion of soy protein isolate (180 parts by weight), and after a mild reaction at 65°C for 10 hours, the free amino content decreases by 10%, retaining more of the protein's functional properties. The antioxidant formulation has a high ascorbate palmitate content (0.14 wt%), strengthening the synergistic antioxidant protection at the lipid phase and oil-water interface. The microcapsule powder has a relatively large median particle size (22 μm), and the mild process conditions are suitable for large-scale, low-cost production. The fermentation substrate contains a high proportion of corn flour (62 parts by weight), providing a sufficient energy base, with an inoculum size of 2 × 10⁻⁶. 6 The CFU / g was gently fermented at 31°C for 60 hours until pH 4.8. This gentle fermentation condition helps retain heat-sensitive nutrients in the raw materials. This example primarily illustrates the feasibility of the formulation and process under conditions of a higher proportion of fermentation substrate, and the performance of the microencapsulated powder shown in Table 1.

[0120] Example 4

[0121] This embodiment prepares a fermented feed to increase the Omega-3 content of broilers, comprising 97 parts by weight of fermentation substrate and 3 parts by weight of Omega-3 fatty acid microcapsule powder.

[0122] I. Preparation of Covalently Conjugated Wall Materials

[0123] A1. Raw material preparation: Mix 110 parts by weight of soy protein isolate and 190 parts by weight of maltodextrin evenly, and add deionized water to make the water content of the mixture 6 wt%.

[0124] A2. Covalent combination reaction: The mixture obtained in step A1 was placed in a sealed container and reacted at 78°C for 22 hours.

[0125] A3. Endpoint criterion: The free amino content was determined by the trinitrobenzenesulfonic acid method. The reaction was stopped when the free amino content of the reaction product decreased by 23% relative to the mixture obtained in step A1.

[0126] A4. Post-processing: The reaction product of this embodiment is crushed and passed through a 95-mesh sieve to obtain the covalently bonded wall material of this embodiment.

[0127] II. Preparation of Omega-3 fatty acid microcapsule powder

[0128] B1. Oil Phase Premix: Flaxseed oil and herring oil were mixed at a mass ratio of 15:85 to obtain a mixed oil. Based on the mass of the mixed oil in this embodiment, 0.18 wt% of DL-α-tocopherol (potency 500 IU / g) and 0.18 wt% of L-ascorbic acid-6-palmitate (content of 40.3 wt% based on vitamin C) were added, and the mixture was stirred at 58°C for 55 min to obtain an oil phase premix. In this embodiment, the mass ratio of α-tocopherol to ascorbic acid palmitate was 1:1.

[0129] B2. Aqueous phase preparation: The covalently bonded wall material of this embodiment was dispersed in deionized water and stirred at 55°C for 50 min to obtain a wall material aqueous phase with a mass fraction of 23 wt%.

[0130] B3. Emulsification: The oil phase premix obtained in step B1 is added to the water phase of the wall material obtained in step B2. The mass ratio of the mixed oil in the oil phase premix to the covalently bonded wall material of this embodiment, calculated on a dry basis, is controlled to be 35:65. Emulsification is carried out by high-speed shearing at a speed of 18,000 r / min and an emulsification time of 9 min to obtain the emulsion product.

[0131] B4. Homogenization: The emulsion obtained in step B3 is homogenized three times at 55 MPa to obtain an emulsion.

[0132] B5. Drying: The emulsion obtained in step B4 was spray-dried at an inlet air temperature of 185°C and an outlet air temperature of 88°C. The resulting powder had a water content of 3 wt% and a surface oil content of 1.8 wt% (determined by Soxhlet extraction with petroleum ether at an extraction temperature of 60°C for 4 hours), thus obtaining the Omega-3 fatty acid microcapsule powder of this embodiment. The median particle size D50 of the Omega-3 fatty acid microcapsule powder of this embodiment was 27 μm (determined by a laser particle size analyzer, with anhydrous ethanol as the dispersion medium; the sample was added to the dispersion medium and shaken for 5 min before measurement), and the peroxide value was 0.5 meq / kg (determined according to GB5009.227-2023, calculated based on the mass of the oil phase extracted from the Omega-3 fatty acid microcapsule powder of this embodiment).

[0133] III. Preparation of Fermentation Substrate

[0134] C1. Raw material preparation: Mix 68 parts by weight of corn kernels, 17 parts by weight of soybean meal, and 6 parts by weight of flaxseed meal (without adding molasses), and add water to make the moisture content of the mixture 29 wt%.

[0135] C2. Sealed fermentation: Inoculate the mixture obtained in step C1 with Lactobacillus acidophilus at a rate of 8 × 10⁸. 7The concentration was CFU / g, and then the mixture was sealed and fermented at 36.5℃ for 90 hours. At the end of the fermentation, the pH value of the material was 4.0.

[0136] C3. Drying: The fermentation product of this embodiment is dried at 58°C to a water content of 12wt% by a belt dryer to obtain the fermentation substrate of this embodiment.

[0137] IV. Preparation of Fermented Feed

[0138] When the temperature of the fermentation substrate in this embodiment drops to 28°C, 3 parts by weight of the Omega-3 fatty acid microcapsule powder in this embodiment are added to 97 parts by weight of the fermentation substrate in this embodiment and mixed thoroughly to obtain the fermented feed of this embodiment. The moisture content of the fermented feed obtained in this embodiment is 12 wt%.

[0139] Example 4 Features: This example employs a formulation design with an extremely high proportion of fermentation substrate, reaching 97 parts by weight, maximizing the bioconversion function of the fermented feed. The microcapsule powder is added at 3 parts by weight, providing essential Omega-3 nutritional supplementation. The covalently conjugated wall material contains a high proportion of maltodextrin (190 parts by weight), undergoing deep reaction at a high temperature of 78°C for 22 hours, resulting in a 23% reduction in free amino content and the formation of highly cross-linked glycoprotein conjugates, providing strong encapsulation protection. The oil phase formulation contains 85% herring oil, significantly enriched with DHA and EPA, and features a high amount of antioxidants (both 0.18 wt%), synergistically protecting the stability of highly unsaturated fatty acids. The median particle size of the microcapsule powder reaches 27 μm, close to the allowable particle size range of the technical solution, with an extremely low peroxide value (0.5 meq / kg), demonstrating that the enhanced antioxidant formulation and strict process control effectively protect the quality of Omega-3 fatty acids. The fermentation substrate uses corn kernels as the main energy source, with relatively small amounts of soybean meal and flaxseed meal added. No molasses is added, and a high inoculum of Lactobacillus acidophilus (8×10⁶) is used. 7 The microencapsulated powder (CFU / g) was deeply fermented at 36.5℃ for 90 hours, reducing the pH to 4.0 and creating a highly acidic fermentation environment that effectively inhibited the growth of harmful bacteria and extended the shelf life of the feed. The drying temperature of 58℃ was close to the allowable range of the process, resulting in a final moisture content of 12wt%, which reduced drying energy consumption while ensuring product stability. This example mainly illustrates the feasibility of the formulation and process under extremely high fermentation substrate ratios, and the performance of the microencapsulated powder shown in Table 1.

[0140] Examples 2-4 are mainly used to illustrate the feasibility of preparing fermented feed and its microcapsule powder under different formulation / process parameters. The performance data of the microcapsule powder of Examples 2-4 are shown in Table 1. In addition, the storage stability, mixing abrasion stability and broiler feeding verification of the final fermented feed of Examples 2-4 were carried out according to the above test methods. The relevant data are shown in Table 2 and Table 3, respectively.

[0141] Example 5

[0142] This embodiment is used to verify the promoting effect of the fermented feed of the present invention on Omega-3 deposition in broiler tissues.

[0143] I. Experimental Animals and Grouping

[0144] A total of 240 healthy white-feathered broiler chickens were selected and randomly divided into a blank control group, Example 1-4 groups, Comparative Example 9 groups, and Comparative Example 10 groups, with 6 replicates per group and 10 chickens per replicate (half male and half female). The pre-trial period was 7 days, and the formal trial period was 42 days. All groups were kept under the same feeding and management conditions, with free access to feed and water.

[0145] II. Experimental Diet Setting

[0146] All groups had the same basal diet composition, with the blank control group fed the basal diet. Group 1 of Example 1 had 5.0 wt% of the fermented feed prepared in Example 1 added to its basal diet. Groups 9 and 10 of Comparative Examples had 5.0 wt% of the fermented feed prepared in Comparative Examples 9 and 10, respectively, added to their basal diets. The broiler feeding verification of Examples 2–4 was conducted separately using the same experimental design as Example 5, with 5.0 wt% of the corresponding fermented feed prepared in the example added to the basal diet. The results are listed in Table 3.

[0147] III. Sample Collection and Testing

[0148] After the experiment, two broilers were randomly selected from each replicate, and samples of breast and / or leg muscles were collected. Gas chromatography was used to determine the content of α-linolenic acid (ALA), eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), total n-3 PUFA, and the n-6 / n-3 ratio in the muscle tissue; mean daily weight gain, mean daily feed intake, and feed conversion ratio were also recorded.

[0149] IV. Test Results

[0150] The results are shown in Table 3. The contents of ALA, EPA, DHA and total n-3 PUFA in the pectoral muscle of Example 1 group were increased by 471.8%, 255.8%, 161.4% and 234.3% respectively compared with the blank control group, and were superior to Comparative Example 9 and Comparative Example 10. This indicates that the combination design of "covalently conjugated microcapsules + fermentation matrix + low temperature post-addition" adopted in this invention is beneficial to improving the Omega-3 deposition level in broiler tissues.

[0151] Comparative Example 1: This example is essentially the same as Example 1, except that the amount of Omega-3 fatty acid microcapsule powder used is 0.5 parts by weight, and the amount of fermentation substrate is 99.5 parts by weight. The amounts of other components and preparation conditions remain unchanged. This comparative example is mainly used to evaluate the effect of low addition levels of microcapsule powder on the storage stability of the final fermented feed and the Omega-3 deposition effect in broiler tissues.

[0152] Comparative Example 2: This example is essentially the same as Example 1, except that the amount of Omega-3 fatty acid microcapsule powder used is 35 parts by weight, and the amount of fermentation substrate is 65 parts by weight. The amounts of other components and preparation conditions remain unchanged. This comparative example is mainly used to evaluate the effect of high microcapsule powder addition on the storage stability of the final fermented feed and the Omega-3 deposition effect in broiler tissues.

[0153] Comparative Example 3: It is basically the same as Example 1, except that in step B3, the mass ratio of the mixed oil in the oil phase premix to the covalently bonded wall material calculated on a dry basis is 75:25, while the amounts of other components and preparation conditions remain unchanged.

[0154] Comparative Example 4: It is basically the same as Example 1, except that the mass ratio of the mixed oil in the oil phase premixed liquid to the covalently bonded wall material calculated on a dry basis in step B3 is 25:75, while the amounts of other components and preparation conditions remain unchanged.

[0155] Comparative Example 5: It is basically the same as Example 1, except that the covalently combined wall material is prepared without Maillard reaction. The wall material is obtained by directly mixing 150 parts by weight of soy protein isolate and 125 parts by weight of maltodextrin and passing the mixture through an 80-mesh sieve. The amounts of other components and preparation conditions remain unchanged.

[0156] Comparative Example 6: It is basically the same as Example 1, except that the covalent combination reaction in step A2 is carried out at 50°C for 2 hours. The reaction is stopped when the free amino content decreases by 3%. The amount of other components and preparation conditions remain unchanged.

[0157] Comparative Example 7: It is basically the same as Example 1, except that the covalent combination reaction temperature in step A2 is 90°C and the reaction time is 14h, while the amount of other components and preparation conditions remain unchanged.

[0158] Comparative Example 8: It is basically the same as Example 1, except that the inlet air temperature of spray drying in step B5 is 210°C and the outlet air temperature is 110°C, and the median particle size D50 of the obtained microcapsule powder is 38 μm. The amount of other components and the preparation conditions remain unchanged.

[0159] Comparative Example 9: Basically the same as Example 1, except that only 275 parts by weight of maltodextrin (on a dry basis, equivalent to the sum of the dry weight of soy protein isolate and maltodextrin in the original scheme) was used in the preparation of the wall material, no soy protein isolate was added, and Maillard covalent conjugation reaction was not carried out, while other conditions remained unchanged.

[0160] Comparative Example 10: It is basically the same as Example 1, except that only 275 parts by weight of soy protein isolate (on a dry basis) is used in the preparation of the wall material, no maltodextrin is added, and Maillard covalent conjugation reaction is not carried out, while other conditions remain unchanged.

[0161] Comparative Example 11: It is basically the same as Example 1, except that lactic acid bacteria are not inoculated in step C2, and the raw materials are directly dried in step C3 after being kept at 34°C for 72 hours (i.e. the fermentation substrate raw materials are not fermented). Other conditions remain unchanged.

[0162] Performance testing:

[0163] Determination of median particle size D50. The test subject was Omega-3 fatty acid microcapsule powder. The purpose of the test was to evaluate the particle size distribution characteristics of the microcapsule powder and verify the influence of the process on particle size controllability. The test principle is based on the principle of laser scattering; the scattering intensity of laser light by particles is related to particle size. The particle size distribution was calculated using Mie scattering theory. The experimental method used a laser particle size analyzer (Malvern Mastersizer 3000 or similar instrument). 0.1-0.2 g of sample was dispersed in 50 mL of anhydrous ethanol and ultrasonically dispersed for 5 min (100 W power, 40 kHz frequency). After ensuring uniform dispersion, the sample was immediately injected for testing. The refractive index was set to 1.47, and the absorptivity to 0.01. Measurements were repeated three times, and the average value was taken. Key parameters included a test temperature of 25±2℃, relative humidity <60%RH, and shading controlled at 10-20%. Data processing records D10, D50, D90, and span values ​​(Span = (D90 - D10) / D50), with results expressed as mean ± standard deviation.

[0164] Determination of surface oil content. The test subject was Omega-3 fatty acid microcapsule powder. The purpose of the test was to evaluate the encapsulation efficiency and wall integrity of the microcapsules, and to verify the effectiveness of the spray drying process in controlling surface oil. The test principle involved rapidly extracting unencapsulated free oil from the microcapsule surface using an organic solvent, and calculating the surface oil content by gravimetric method. The experimental method involved accurately weighing 2.0 g of microcapsule powder into a filter paper tube, placing it in a Soxhlet extractor, adding 100 mL of petroleum ether (boiling range 60-90℃), and refluxing at 60℃ for 4 h. After extraction, the petroleum ether solution was transferred to a pre-weighed evaporating dish and allowed to evaporate naturally in a fume hood until no solvent odor remained. The solution was then dried in a 105℃ oven for 30 min until constant weight, cooled, and weighed. Key parameters included extraction temperature 60±2℃, extraction time 4 h, and reflux frequency 4-6 times / min. Data processing was performed as follows: surface oil content (wt%) = extracted oil mass / sample mass × 100%, with results rounded to one decimal place.

[0165] Determination of peroxide value. The test subject was the oil phase extracted from Omega-3 fatty acid microcapsule powder. The purpose of the test was to evaluate the oxidative stability of Omega-3 fatty acids and verify the protective effect of covalently bonded wall materials and antioxidant formulations. The test principle is that peroxides react with potassium iodide to generate free iodine, and the peroxide value is calculated by titration with sodium thiosulfate standard solution. Experimental method: First, total oil was extracted from 5.0g of sample using a chloroform-methanol mixture (2:1, v / v). 2.0-5.0g of the extracted oil was accurately weighed into an iodine flask, dissolved in 30mL of a chloroform-glacial acetic acid mixture (2:3, v / v), and 1mL of saturated potassium iodide solution was added. The mixture was sealed tightly, shaken well, and placed in the dark for 3min. After adding 100mL of water, it was titrated with 0.01mol / L sodium thiosulfate until a pale yellow color was obtained. Starch indicator was added, and titration continued until the blue color disappeared. Key parameters included temperature 20±2℃ and reaction time 3min in the dark. Data processing was performed using the formula: peroxide value (meq / kg) = (Vsample - Vempt) × c × 1000 / moil, with the mass of the oil phase extracted from the microcapsule powder as the baseline.

[0166] Encapsulation efficiency determination. The test subject was Omega-3 fatty acid microcapsule powder. The purpose of the test was to evaluate the encapsulation ability of microcapsules for Omega-3 oil phase and to verify the effectiveness of the emulsification-homogenization-spray drying process. The test principle was to measure the total oil content and the surface oil content separately. The difference between the two was the encapsulated oil content, and the encapsulation efficiency was the percentage of encapsulated oil to total oil. In the experimental method, the total oil content was determined by Soxhlet extraction. 2.0 g of sample was extracted with petroleum ether at 80℃ for 8 h. The surface oil content was extracted according to Experiment 2 at 60℃ for 4 h. The extracts were collected, evaporated to dryness, and weighed separately. The encapsulated oil was equal to the total oil minus the surface oil. Key parameters included total oil extraction at 80℃ / 8 h, surface oil extraction at 60℃ / 4 h, and drying temperature at 105℃. Data processing was performed as follows: encapsulation efficiency (%) = (total oil - surface oil) / total oil × 100%, and the result was rounded to one decimal place.

[0167] Accelerated Oxidative Stability Test (Schaal Oven Method). The test subject was Omega-3 fatty acid microcapsule powder. The purpose of the test was to evaluate the antioxidant stability of the microcapsule powder during storage and verify the long-term effectiveness of the wall material protection and antioxidant system. The test principle was to accelerate the lipid oxidation reaction under high temperature conditions, periodically monitor the changes in peroxide value and TBARS value, and estimate the shelf life at room temperature. The experimental method was to accurately weigh 20g of microcapsule powder and place it in a transparent glass bottle (50mL). The bottle was then placed in a constant temperature incubator at 60±1℃ (relative humidity <30%RH). Samples were taken on days 0, 3, 6, 9, 12, and 15. The peroxide value was measured according to Experiment 3, and the TBARS value (thiobarbituric acid reactant, 532nm colorimetric method) was measured simultaneously. A peroxide value-time curve was plotted, and the failure endpoint was defined as a peroxide value of 5.0 meq / kg. Key parameters included an accelerating temperature of 60±1℃, humidity <30%RH, and a sampling interval of 3 days. Data processing was used to plot oxidation kinetic curves, calculate the induction period (IP), and use Q10=2 to estimate the shelf life at room temperature.

[0168] In vitro simulated digestion release rate determination. The test subject was Omega-3 fatty acid microcapsule powder. The purpose of the test was to evaluate the disintegration and release characteristics of the microcapsules in the digestive tract environment of broilers and to verify the design goal of the wall material being both wear-resistant and capable of effective release. The test principle was to simulate the pH and enzyme environment of the crop, proventriculus, gizzard, and small intestine of broilers and to measure the content of released free fatty acids at regular intervals. The experimental method was as follows: 1.0 g of microcapsule powder was added to 50 mL of simulated crop fluid (pH 5.5, enzyme-free), shaken at 37°C for 30 min, transferred to simulated proventriculus fluid (pH 2.5, pepsin 2000 U / mL), shaken at 37°C for 60 min, and then transferred to simulated small intestinal fluid (pH 6.8, pancreatic lipase 5000 U / mL, bile salts 5 mg / mL), shaken at 37°C for 120 min, and samples were taken at 0, 30, 90, and 210 min, centrifuged (4000 rpm, 10 min), and the supernatant was used to determine the free fatty acid content using the copper soap method. Key parameters included temperature 37±0.5℃, oscillation frequency 150rpm, and liquid-to-solid ratio 50:1. Data processing was performed by calculating the cumulative release rate (%) = released fatty acids / total oil × 100%, and a release curve was plotted.

[0169] Storage stability test of the final fermented feed. The test subjects were the final fermented feeds obtained in the examples and comparative examples. The purpose of the test was to evaluate the actual storage protection effect of the combination of fermentation substrate and microcapsules on Omega-3. The experimental method was to take 200g of each sample and place it in an oxygen-barrier packaging container, and store it at 25℃ and 60% relative humidity. Samples were taken on days 0, 7, 14, and 28, and the peroxide value, TBARS value, and total Omega-3 retention rate were measured. The peroxide value, TBARS value, and total Omega-3 retention rate at 28 days were the main evaluation indicators.

[0170] Mixed abrasion stability test. The test subjects were the final fermented feeds obtained from the examples and comparative examples. The purpose of the test was to evaluate the risk of microcapsule cell breakage under the mechanical action of mixing, conveying, and storage. The experimental method was to place 500g samples in a drum mixer or vibration simulation device and treat them at 60rpm for 30min. The amount of surface oil seepage, pulverization rate, and microcapsule integrity rate were measured before and after treatment. If necessary, optical microscopy or laser particle size distribution was used to assist in characterizing particle breakage. The changes in surface oil seepage increase and microcapsule integrity rate were used as evaluation indicators.

[0171] Determination of fatty acid composition in muscle tissue. The test subjects were pectoral and / or leg muscle samples from broiler chickens in each group of Example 5. The purpose of the test was to evaluate the effect of the fermented feed of the present invention on the deposition of Omega-3 fatty acids in broiler tissue. The experimental method involved taking 5g of homogenized muscle sample, extracting total lipids using a chloroform-methanol mixed solvent, and then determining the fatty acid methyl ester composition using gas chromatography after methylation. The contents of α-linolenic acid (ALA), EPA, DHA, total n-3 PUFAs, and the n-6 / n-3 ratio were quantitatively obtained. Data were expressed as mg / 100g fresh sample or as a percentage of total fatty acids.

[0172] FTIR testing was performed on wall material samples from Examples 1, 5, and 6. The purpose of the test was to characterize whether Maillard covalent bonding occurred between soy protein isolate and maltodextrin and the degree of reaction. The experimental method was as follows: the samples were vacuum-dried at 40°C for 12 hours, then finely ground. 1-2 mg of the sample was thoroughly mixed with 100 mg of dried KBr and compressed into tablets. Fourier transform infrared spectroscopy was used for measurement, with a scanning wavenumber range of 4000 cm⁻¹. -1 Up to 400cm -1 The resolution is 4cm. -1 A total of 32 scans were performed; Figure 1 Select 1800cm -1 Up to 900cm -1 The feature regions are plotted after baseline correction and normalization.

[0173] XPS testing was conducted on wall material samples from Examples 1, 5, and 6. The purpose of the test was to characterize the changes in the chemical states of N1s and C1s with the degree of reaction. The experimental method was as follows: the samples were vacuum-dried at 40°C for 12 hours and then fixed onto conductive tape. X-ray photoelectron spectroscopy was used for measurement, with monochromatic Al Kα as the excitation source and a vacuum degree better than 1×10⁻⁶. -7 Pa; first perform a full spectrum scan, then perform high-resolution scans of N1s and C1s; charge correction is performed using C1s 284.8eV, and Shirley background subtraction and peak separation fitting are used; Figure 2 and Figure 3 High-resolution spectra of N1s and C1s are given respectively.

[0174] DSC thermal analysis was performed on Omega-3 fatty acid microcapsule powders from Example 1 and Comparative Example 3 to evaluate encapsulation integrity and oil phase transition behavior. The experimental method was as follows: 5-10 mg of sample was accurately weighed and placed in an aluminum crucible, sealed, with an empty crucible as a reference. Differential scanning calorimetry (DSC) was used under nitrogen protection at a nitrogen flow rate of 50 mL / min. The sample was first cooled from 25°C to -80°C at a rate of 10°C / min and held for 5 min. Then, the temperature was increased to 40°C at a rate of 10°C / min to obtain the heating curve. Subsequently, the temperature was decreased to -80°C at a rate of 10°C / min to obtain the cooling curve. Figure 5 The heating curve is obtained from the temperature scan. Figure 6 The cooling curve was obtained from the subsequent cooling scan.

[0175] Figure 1 This is a comparison image of FTIR Maillard covalently coupled and physically hybrid wall materials from Example 1 and Comparative Example 5, with the scanning wavenumber range fixed at 1800 cm⁻¹. -1 Up to 900cm -1 The absorbance is normalized intensity; the spectrum is presented as a continuous curve without grid lines; the varying parameters are compared between Example 1 (covalently bonded wall material) and Example 5 (physically mixed wall material). Example 1 was measured at 1639 cm⁻¹. -1 1548cm -1 1367cm -1 The characteristic regions exhibit more coordinated peak shapes and relative intensity ratios, accompanied by fingerprint region changes related to the fusion. In contrast, the peak combinations in Comparative Example 5 are closer to simple superposition of components, indicating that Example 1 forms more stable interfacial chemical interactions and structural rearrangements, which is beneficial to improving encapsulation stability and reducing the risk of free oil exposure. This supports the correctness of the solution to achieve effective encapsulation through reactive wall materials.

[0176] Figure 2 The XPS N1s chemical state of Examples 1, 5, and 6 varies with the degree of reaction. Fixed parameters are the binding energy range of 404 eV to 396 eV, normalized intensity, and high-resolution superimposed curves. Variations are the differences in nitrogen chemical state distribution caused by the varying degrees of wall material reaction from Example 1 to Comparative Examples 5 and 6. In Example 1, the peak distribution near 399.5 eV and 400.8 eV more closely resembles the combined characteristics of the nitrogen environment after covalent reaction. In contrast, the peak shapes of Comparative Examples 5 and 6 are more biased towards incompletely reacted or residual amino groups, indicating that the interfacial reaction in Example 1 is more complete and forms a more stable chemical bonding network. This provides evidence for reducing the exposure of oxidation-sensitive components and improving antioxidant stability, proving that the interfacial construction pathway of this scheme is effective.

[0177] Figure 3XPS graphs of C1s carbon chemical state changes for Examples 1, 5, and 6 are shown. Fixed parameters include binding energy range of 292 eV to 284 eV, normalized intensity, and high-resolution superimposed curves. Variation parameters represent the changes in the proportions of CC / CH, CN, CO, and C=O related peaks caused by different sample wall material structures and reaction degrees. Example 1 exhibits more pronounced oxygen- and nitrogen-containing bonded component characteristics in the 284.8 eV to 288.8 eV range, consistent with changes in the carbon environment after covalent bonding. Comparative Examples 5 and 6 show peak shapes that are more inclined towards a higher proportion of a single carbon environment due to loose mixing. This indicates that Example 1 more readily forms a dense chemical bonding interface and a structure with enhanced polar interactions, which helps improve embedding efficiency and inhibit lipid migration, thus verifying the correctness of this scheme from the perspective of carbon chemical state.

[0178] Figure 4 The main evidence plots are the laser particle size differential distribution curves for Example 1 and Comparative Example 8. The fixed parameters are: laser particle size distribution method; x-axis: logarithmic particle size distribution ranging from 1 μm to 200 μm; y-axis: volume distribution. The varying parameters are the differences in particle size distribution caused by differences in sample formulation and structure. The representative samples are Example 1 and Comparative Example 8. Example 1 shows a more concentrated distribution peak with a D50 of 17.0 μm corresponding to the main peak position. The narrower distribution indicates a more uniform particle formation and solidification process. In contrast, Comparative Example 8 has a D50 of 38.0 μm and a wider distribution, suggesting more significant agglomeration or uneven particle formation. This demonstrates that the proposed method can achieve more stable and controllable microcapsule particle size and better dispersibility, laying the foundation for subsequent release and stability performance. From the perspective of particle size controllability, this proves the effectiveness of the proposed method.

[0179] Figure 5 The images show the melting peak suppression and encapsulation integrity of the heating curves obtained from DSC temperature scanning of Example 1 and Comparative Example 3. The fixed parameters are differential scanning calorimetry (DSC) as the characterization method, a temperature range of -80℃ to 40℃, and a continuous curve showing heat flow with temperature. The varying parameters are the differences in oil phase melting peak intensity caused by differences in the encapsulation structure of the samples. The representative samples are Example 1 and Comparative Example 3. In Example 1, the melting-related peaks near -42℃ and -33℃ are weaker and flatter, indicating a lower proportion of free or weakly bound oil phases, consistent with the encapsulation efficiency of 88.5% and surface oil of 1.0 wt%. In Comparative Example 3, the peaks are more pronounced, suggesting the presence of more fusible free oil or unstable encapsulated phases, consistent with its encapsulation efficiency of 68.3% and surface oil of 4.2 wt%. This demonstrates that the encapsulation structure formed by this method is more complete and can effectively reduce free oil.

[0180] Figure 6The images show the crystallization peak suppression curves obtained from DSC cooling scans of Example 1 and Comparative Example 3. The fixed parameters are differential scanning calorimetry (DSC) as the characterization method, a temperature range of -80℃ to 40℃, and a continuous curve representing heat flow with temperature. The varying parameters represent the differences in oil phase crystallization behavior caused by different embedding structures. The representative samples are Example 1 and Comparative Example 3. In Example 1, the crystallization-related peaks near -47℃ and -40℃ are weaker or more dispersed, indicating that the oil phase's crystallization freedom is reduced due to the constraints of the wall material network and interfacial bonding, thus reducing the risk of phase separation and migration. In Comparative Example 3, the more prominent crystallization peaks suggest that the oil phase is more likely to form a crystallizable phase and undergo phase rearrangement, consistent with its higher surface oil content and lower embedding efficiency. This indicates that the proposed scheme can improve phase stability and reduce oil phase migration before release by enhancing interfacial bonding and network constraints, further proving the correctness of the scheme.

[0181] Figure 7 The graphs show the cumulative release rate over time for in vitro simulated digestion of Examples 1, 6, and 7. Fixed parameters include in vitro simulated digestion release testing as the characterization method, a time range of 0 min to 210 min, and the cumulative release rate on the ordinate from 0% to 100%. A continuous curve connects each measurement point. Variable parameters represent the differences in release rate and final release amount due to differences in sample wall material structure. Examples 1, 6, and 7 are representative samples. Example 1 exhibits a flatter release curve from 0 to 210 min, with a cumulative release rate of 82.3% at 210 min, demonstrating more controlled release behavior. This is consistent with the stability indicators of a longer accelerated induction period of 12.5 days and a lower peroxide value of 2.5 meq / kg. Comparative Examples 6 and 7 show faster early release, reaching 73.5% and 77.0% respectively, with shorter induction periods. This indicates insufficient interfacial barrier and structural integrity, leading to faster diffusion or the formation of higher permeability channels. This demonstrates that the proposed scheme can achieve a more stable and controllable release process while maintaining releaseability, thus verifying the rationality and effectiveness of the scheme design.

[0182] Figure 8 This is a macroscopic optical photograph of the Omega-3 fatty acid microcapsule powder (obtained by spray drying) from Example 1. The sample was prepared using the Maillard reaction product of soy protein isolate (SPI) and maltodextrin (MD) as the wall material, reacted at 70°C for 14 hours, and then spray-dried. The resulting powder had a moisture content of 5 wt% and a surface oil content of 1.0 wt%. The powder was milky white to light creamy yellow with a matte finish, demonstrating that moderate glycosylation modification and low surface oil content effectively controlled particle color and light scattering, achieving good sensory quality of the powder.

[0183] Figure 9This is a scanning electron microscope (SEM) image of the Omega-3 fatty acid microcapsule powder from Example 1. The sample was prepared under the same spray drying conditions as in Example 1: emulsification shear speed of 12500 r / min, shear time of 5 min, homogenization pressure of 40 MPa, two homogenization passes, and an oil phase premixing temperature of 45 °C and a stirring time of 35 min. The aqueous phase of the wall material had a mass fraction of 15 wt%, and the mass ratio of the mixed oil to the covalently bonded wall material (calculated on a dry basis) was 50:50. The particles were predominantly nearly spherical, with typical wrinkles or slight depressions observed on the surface from spray drying. The overall structure was continuous and intact, consistent with the statistical results of micron-level particle size. This indicates that high-speed shearing combined with high-pressure homogenization can obtain a stable emulsion and form a dense outer layer structure that helps reduce surface oil migration. Morphologically, this supports the feasibility and rationality of achieving a surface oil content of 1.0 wt%.

[0184] As can be seen from the performance of the embodiments and comparative examples in Tables 1-3, the present invention, through the combined design of "covalently combined wall material, oil-to-wall ratio matching, synergistic fermentation substrate, and low-temperature post-addition," makes the embodiments generally superior to the comparative examples in key indicators such as surface oil content, peroxide value, encapsulation efficiency, storage retention rate, mixed abrasion stability, and n-3 deposition in broiler muscle. Among them, Example 1 shows the most balanced performance in terms of final fermented feed stability and feeding effect, indicating that the 85:15 ratio is more conducive to balancing processing stability and bioavailability; Examples 2 and 4 demonstrate the feasibility of high loading and high antioxidant, respectively, while Example 3 proves that the scheme is still effective at lower addition levels. Conversely, the lack of wall material synergy, deviation of the oil-to-wall ratio, insufficient or excessive Maillard reaction, and the cancellation of fermentation treatment all lead to a decrease in oxidation control, retention rate, and deposition efficiency.

[0185] Table 1 Comparison of Microcapsule Powder Performance

[0186] Table 2 Comparison of Storage and Mixing Stability of Final Fermented Feed

[0187] Table 3 Comparison of Omega-3 deposition in broiler chickens based on feeding practices

[0188] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that any equivalent structural transformations made under the concept of the present invention and using the contents of the specification and drawings of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A fermented feed for increasing Omega-3 content in broilers, characterized in that, By weight, it includes: 75–97 parts by weight of fermentation substrate; 3–25 parts by weight of Omega-3 fatty acid microcapsule powder; The sum of the mass parts of the fermentation substrate and the Omega-3 fatty acid microcapsule powder is 100 parts by mass; The Omega-3 fatty acid microcapsule powder comprises an Omega-3 oil phase and a covalently bonded wall material; The covalently bonded wall material is a glycoprotein conjugate obtained by Maillard reaction of soy protein isolate and maltodextrin; The mass ratio of the Omega-3 oil phase to the covalently bonded wall material is 35:65 to 60:40; The median particle size D50 of the Omega-3 fatty acid microcapsule powder is 12–27 μm, and the surface oil content is 0.8–1.8 wt%, wherein the surface oil content is calculated based on the mass of the Omega-3 fatty acid microcapsule powder; the peroxide value is 0.5–3.5 meq / kg, wherein the peroxide value is calculated based on the mass of the oil phase extracted from the Omega-3 fatty acid microcapsule powder.

2. The fermented feed according to claim 1, characterized in that, The covalently bonded wall material is prepared by the following steps: A1. Raw material preparation: Mix 110–180 parts by weight of soy protein isolate with 80–190 parts by weight of maltodextrin, and add deionized water to make the water content of the mixture 6–10 wt%. A2. Covalent combination reaction: Place the mixture obtained in step A1 in a sealed container and react at 65–78°C for 10–22 h; A3. Endpoint criterion: The reaction is stopped when the free amino content of the reaction product decreases by 10–23% relative to the mixture obtained in step A1; A4. Post-processing: The reaction product is crushed and passed through a 70-95 mesh sieve to obtain the covalently bonded wall material.

3. The fermented feed according to claim 1, characterized in that, The Omega-3 fatty acid microcapsule powder is prepared by the following steps: B1. Oil phase premix: Flaxseed oil and herring oil are mixed to obtain a mixed oil; α-tocopherol and ascorbyl palmitate are added based on the mass of the mixed oil, and the mixture is stirred and mixed at 35–58°C for 20–55 min to obtain an oil phase premix. B2. Aqueous phase preparation: The covalently bonded wall material is dispersed in deionized water and stirred at 30–55°C for 20–50 min to obtain an aqueous phase of wall material with a mass fraction of 10–23 wt%. B3. Emulsification: The oil phase premix obtained in step B1 is added to the water phase of the wall material obtained in step B2. The mass ratio of the mixed oil in the oil phase premix to the covalently bonded wall material calculated on a dry basis is controlled to be 35:65 to 60:

40. Emulsification is carried out by high-speed shearing at a speed of 8000–18000 r / min and an emulsification time of 3–9 min to obtain the emulsion product. B4. Homogenization: Homogenize the emulsion obtained in step B3 at 30–55 MPa 1–3 times to obtain an emulsion; B5. Drying: The emulsion obtained in step B4 is spray-dried at an inlet air temperature of 160–185°C and an outlet air temperature of 75–88°C to obtain Omega-3 fatty acid microcapsule powder with a water content of 3–6 wt% and a surface oil content of 0.8–1.8 wt%.

4. The fermented feed according to claim 1, characterized in that, The fermentation substrate is prepared through the following steps: C1. Raw material preparation: Mix 45–68 parts by weight of corn flour or corn grits, 17–32 parts by weight of soybean meal, 6–16 parts by weight of flaxseed meal, and 0–2.5 parts by weight of molasses, and add water to make the moisture content of the mixture 29–37 wt%. C2. Sealed fermentation: Lactic acid bacteria are inoculated into the mixture obtained in step C1. The lactic acid bacteria are selected from Lactobacillus plantarum, Lactobacillus acidophilus, or a combination thereof. The inoculation amount is 2 × 10⁻⁶. 6 –8×10 7 CFU / g, and then sealed and fermented at 31–36.5℃ for 60–90 h. The pH of the material at the end of fermentation is 4.0–4.

8. C3. Drying: The fermentation product is dried at 45–58°C to a moisture content of 6–12 wt% by hot air drying or belt drying to obtain the fermentation substrate.

5. The fermented feed according to claim 1, characterized in that, The Omega-3 fatty acid microcapsule powder is added and mixed when the temperature of the fermentation substrate does not exceed 38°C, and the resulting fermented feed has a moisture content of 6–12 wt%.

6. The fermented feed according to claim 3, characterized in that, In step B1, the mass ratio of the flaxseed oil to the herring oil is 15:85 to 70:

30.

7. The fermented feed according to claim 6, characterized in that, In step B1, 0.06–0.18 wt% of α-tocopherol and 0.05–0.18 wt% of ascorbate palmitate are added based on the mass of the mixed oil, and the mass ratio of α-tocopherol to ascorbate palmitate is 1:2.3 to 3:1, wherein the ascorbate palmitate is L-ascorbic acid-6-palmitate.

8. A method for preparing fermented feed for increasing Omega-3 content in broilers as described in any one of claims 1-7, characterized in that, Includes the following steps: D1. Preparation of fermentation substrate; D2. Preparation of Omega-3 fatty acid microcapsule powder; D3. Mixing: When the temperature of the fermentation substrate does not exceed 38°C, the Omega-3 fatty acid microcapsule powder is added to the fermentation substrate and mixed to obtain the fermented feed.

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