Pet nutritional composition capable of reducing peculiar smell of excrements and preparation method of pet nutritional composition

Abstract

The invention discloses a pet nutritional composition capable of reducing peculiar smell of excrements and a preparation method of the pet nutritional composition. The pet nutritional composition is prepared by the following steps: performing pre-emulsification and high-shear emulsification on functional components such as ethyl lactate, pig blood protein peptide, a pericarpium citri reticulatae extract, a yucca extract and phytic acid; the microcapsule is encapsulated in a sodium alginate-calcium chloride gel network integrated with nano zeolite powder and agaro-oligosaccharide through ionic gelation to form a functional microcapsule base material; meanwhile, the lactobacillus is embedded in the sodium alginate-chitosan composite gel microcapsule by adopting an emulsification-internal gelation technology. And finally, mixing the prebiotics with mannan oligosaccharide and fructo-oligosaccharide compounded prebiotics. Through split type embedding and differentiated wall material design, the problems that probiotics are prone to inactivation and components interfere with one another are solved, intestinal tract targeted rapid release of functional components and sequential precise delivery of the probiotics are achieved, a triple deodorization mechanism of source inhibition, efficient adsorption and micro-ecological regulation is synergistically exerted, and the deodorization effect is good. The deodorization efficiency and the action durability are obviously improved.

Description

Technical Field

[0001] This invention belongs to the field of pet food technology, specifically, it relates to a pet nutritional composition that can reduce the odor of excrement and its preparation method. Background Technology

[0002] With the increasing popularity of pet ownership, the odor problem caused by pet excrement has become increasingly prominent, posing a significant threat to household hygiene and harmonious coexistence between humans and pets. This odor primarily originates from undigested protein in the pet's diet. This protein undergoes microbial fermentation in the pet's intestines, producing foul-smelling substances such as ammonia, hydrogen sulfide, indole, and skatole. Current technologies typically employ methods such as adjusting the diet formula, directly adding probiotics or enzyme preparations, and using chemical deodorizers or plant extracts to address this issue. However, these methods all have significant limitations. While adjusting the diet can reduce some undigested protein, it is difficult to effectively intervene in the complex fermentation process within the intestines. Directly added probiotics and other active ingredients are easily deactivated during processing, storage, and in the acidic environment of the stomach, resulting in insufficient effective doses reaching the intestines. Directly mixed plant extracts and other ingredients face problems such as premature degradation in gastric juices and improper release timing, failing to fully exert their effects at the target site.

[0003] A deeper technical challenge lies in the lack of systematic collaborative design and precise delivery strategies in existing solutions. Most technologies focus only on a single deodorization pathway, failing to effectively integrate multiple mechanisms such as odor generation inhibition, efficient adsorption, and gut microbiota regulation. Even with microencapsulation technology, conventional carriers suffer from insufficient mechanical strength and poor targeted release performance, making it impossible to simultaneously ensure the stability of functional ingredients in the acidic environment of the stomach and their rapid and efficient release in the intestinal environment. Furthermore, while existing encapsulation technologies such as electrostatic droplet generation can prepare high-performance microspheres under laboratory conditions, their processing throughput is low and difficult to scale up. Additionally, encapsulated probiotics still suffer from impaired activity and delayed colonization, resulting in slow deodorization activation.

[0004] Therefore, there is an urgent need in this field for an innovative technical solution that can achieve synergistic effects of multiple mechanisms, has precise targeted delivery capabilities, and can effectively ensure the activity of probiotics and promote their intestinal colonization through scalable processes, so as to fundamentally solve the problem of odor in pet excrement. Summary of the Invention

[0005] The present invention aims to overcome the shortcomings of the prior art, and the specific contents are as follows: A method for preparing a pet nutritional composition that can reduce the odor of feces includes the following steps: (1) Preparation of component A: Ethyl lactate and maltodextrin were weighed at a mass ratio of 1:1 and respectively prepared into solutions with distilled water. The concentration of the ethyl lactate solution was 100~150 g / L and the concentration of the maltodextrin solution was 250~350 g / L. The two solutions were then stirred and mixed evenly at 25~35℃ at a stirring speed of 300~500 rpm for 10~20 minutes to obtain component A. (2) Preparation of component B: Weigh porcine blood protein peptide (molecular weight ≤1000Da), tangerine peel extract (total flavonoid content ≥20%), monoglyceride and rapeseed oil in a mass ratio of 10:5:30:45. Dissolve porcine blood protein peptide, tangerine peel extract and monoglyceride in rapeseed oil at 40~50℃ and stir until completely homogeneous to obtain component B; (3) Preparation of component C: Yucca extract (containing 45% steroidal saponins) and phytic acid were mixed at a mass ratio of 2:1 and prepared into a solution with a concentration of 100~200 g / L using distilled water as the aqueous phase. Then, under stirring conditions of 50~60℃ and 200~400 rpm, the aqueous phase was slowly added to component B (oil phase) and stirred continuously for 5~15 minutes to achieve sufficient pre-dispersion in the oil phase, resulting in component C in a crude emulsion state. The key to step (3) is to pre-disperse the aqueous phase containing yucca extract (containing 45% steroidal saponins) and phytic acid in the oil phase of component B through gentle stirring, forming an unstable crude emulsion. This pre-dispersion process aims to ensure that the water-soluble functional components are evenly distributed in the system before subsequent high-shear emulsification, avoiding component aggregation or uneven emulsification caused by direct addition, thus laying the foundation for the formation of a uniform and stable final emulsion in step (5).

[0006] (4) Preparation of component D: Nanoscale zeolite powder and agar oligosaccharide (degree of polymerization of 2~8) are dry mixed at a mass ratio of 1:3 to obtain a mixture. Then, the mixture is slowly added to component C. The amount of the mixture added is 1~5% of the mass of the final component C. The mixture is dispersed under ultrasonic power of 300~500W for 5~10 minutes to form a uniform premixed system, i.e. component D. (5) Mixing and emulsification: Mix component A and component D at a mass ratio of 1:3, and use a high-shear mixing emulsifier at a speed of 15,000 to 18,000 rpm for 10 to 20 minutes at a temperature of 45 to 55°C to form an emulsion; (6) Ion gelation: Add sodium alginate solution with a mass concentration of 20~40 g / L to the emulsion. The mass ratio of sodium alginate to emulsion is 1:5. After stirring evenly, add it dropwise to calcium chloride solution with a mass concentration of 30~50 g / L at a dropping rate of 1~2 mL / min to form gel microspheres. (7) Spray drying: The gel microspheres are spray dried at an inlet temperature of 160~180℃ and an outlet temperature of 85~95℃, with an atomization pressure of 0.2~0.4MPa, to obtain loose functional microcapsule base material with a moisture content ≤5%; (8) Preparation of probiotic microcapsules: Using emulsification-internal gelation technology, Lactobacillus (live count ≥1×10^9 CFU / g) was uniformly dispersed in a sodium alginate solution with a mass concentration of 20~30 g / L as the aqueous phase; this aqueous phase was added to a vegetable oil phase containing an appropriate amount of emulsifier, and high-speed shearing was used to form W / O type droplets; then a calcium chloride acetic acid solution with a mass concentration of 20~30 g / L was slowly added, and calcium ions diffused into the droplets to initiate an internal gelation reaction; after solid-liquid separation and washing, the wet microspheres were immersed in a chitosan acetic acid solution with a mass concentration of 5~15 g / L and reacted for 10~20 minutes to form sodium alginate-chitosan composite gel microspheres; finally, the probiotic microcapsules were obtained by fluidized bed drying or vacuum low-temperature drying. (9) Post-processing: The functional microcapsule base material obtained in step (7), the probiotic microcapsules obtained in step (8), and the probiotic fermentation promoter powder (which is a mixture of mannan oligosaccharide and fructooligosaccharide in a mass ratio of 1:1) are fully mixed in a mass ratio of (75~85):(5~15):(5~10) and then granulated or pressed. When granulating, 2~5% of the binder hydroxypropyl methylcellulose is added. When pressing, the pressure is 10~20MPa.

[0007] Further, in step (1), the concentration of the ethyl lactate solution is 125 g / L, the concentration of the maltodextrin solution is 300 g / L, the mixing temperature is 30℃, the stirring speed is 400 rpm, and the time is 15 minutes. Optimizing the solution concentrations and mixing parameters of ethyl lactate and maltodextrin ensures that component A forms a stable homogeneous system, providing an ideal aqueous phase basis for the subsequent emulsification process.

[0008] Furthermore, the molecular weight of the porcine blood protein peptides mentioned in step (2) is 500~800 Da, the total flavonoid content of the tangerine peel extract is 25%, and the dissolution temperature is 45℃. By limiting the molecular weight range and dissolution temperature of the porcine blood protein peptides, the digestion and absorption efficiency of small molecule peptides is ensured, while avoiding the destruction of heat-sensitive active ingredients in the tangerine peel extract by excessively high temperatures.

[0009] Further, in step (3), the mass ratio of yucca extract (containing 45% steroidal saponins) to phytic acid is 2:1, the solution concentration is 150 g / L, the mixing temperature is 55℃, the stirring speed is 300 rpm, and the time is 10 minutes. Yucca extract (containing 45% steroidal saponins) is a complex natural plant extract. Its main active ingredients have been fully confirmed by existing research, including (1) steroidal saponins: the most core and thoroughly studied functional components in yucca extract (containing 45% steroidal saponins). As a natural surfactant, it helps to clear intestinal waste and change cell membrane permeability to promote nutrient absorption; (2) polysaccharides: specifically refers to functional oligosaccharides formed by multiple monosaccharides linked by glycosidic bonds. They cannot be broken down by the animal's own digestive enzymes, but can act as prebiotics to promote the growth and reproduction of beneficial bacteria in the lower part of the intestine; (3) Polyphenols: including resveratrol and linfenglan polyphenols, which have a strong binding ability to amino groups, and are speculated to play a role in reducing ammonia, while also having anti-infective effects. Among the above components, saponins are considered to be the core substances that achieve the main functions of deodorization (especially inhibiting urease and reducing ammonia generation) and improving intestinal health. By precisely controlling the mass ratio of yucca extract (containing 45% steroidal saponins) to phytic acid, a multi-level synergistic effect is achieved. The two complement each other at their sites of action: phytic acid chelates metal ions in the intestinal tract to inhibit protein fermentation, while yucca extract (containing 45% steroidal saponins) inhibits urease activity and reduces ammonia production in the intestinal tract. At the molecular level, yucca saponins and phytic acid phosphate groups form a stable complex that can more effectively encapsulate sulfur-containing amino acids and tryptophan, effectively improving the inhibition rate of ammonia, hydrogen sulfide, and skatole. At the same time, relying on the pH-responsive release characteristics, phytic acid remains stable in the acidic environment of the stomach, while yucca extract (containing 45% steroidal saponins) has the best activity in the alkaline environment of the intestine, forming a synergistic chain of time-release, further extending the duration of the deodorizing effect.

[0010] Furthermore, in step (4), the average particle size of the nano-sized zeolite powder is 50-100 nm, the degree of polymerization of the agar oligosaccharide is 4-6, the amount of component D added is 3% of the total mass of the mixture of component C, the ultrasonic dispersion power is 400 W, and the time is 8 minutes. By limiting the particle size of the nano-zeolite and the degree of polymerization of the agar oligosaccharide, it is ensured that the nanomaterials are uniformly dispersed in the system and give full play to the "molecular bridge" effect, thereby enhancing the density and mechanical strength of the microcapsule wall material.

[0011] Furthermore, the mixing and emulsification temperature in step (5) is 50°C, the shear rate is 16000 rpm, and the time is 15 minutes. Optimizing the emulsification process parameters forms an emulsion with uniform particle size distribution and good stability, laying the foundation for the subsequent ion gelation preparation of structurally regular microcapsules.

[0012] Further, in step (8), the concentration of sodium alginate solution is 20-30 g / L, the concentration of chitosan solution is 8-12 g / L, and the reaction time is 15 minutes. By optimizing the reaction conditions of the sodium alginate-chitosan composite gel, a dense polyelectrolyte composite film is formed on the surface of the probiotic microcapsules, significantly improving their protective effect in the gastric acid environment.

[0013] This invention also provides a pet nutritional composition that can reduce the odor of feces. The composition is a solid granule comprising a functional microcapsule base, probiotic microcapsules, and prebiotics. The wall material of the functional microcapsule base is a sodium alginate-calcium chloride gel network, incorporating nano-zeolite powder and agar oligosaccharides. Its core material comprises ethyl lactate, porcine blood protein peptides, tangerine peel extract, yucca extract (containing 45% steroidal saponins), and phytic acid. The wall material of the probiotic microcapsules is a sodium alginate-chitosan composite gel, and its core material contains lactobacillus. The prebiotics are a mixture of mannan oligosaccharides and fructooligosaccharides in a 1:1 mass ratio. The pet nutritional composition is added to the pet food at a weight percentage of 0.5-5%. This pet nutrition composition has a clear multi-level structural feature. The functional microcapsules and probiotic microcapsules achieve sequential release in the intestine. First, the deodorizing ingredients are released rapidly, followed by the release of highly active probiotics, achieving the dual effects of immediate deodorization and long-term regulation. Moreover, by scientifically limiting the range of addition in pet food, it ensures that the effective ingredients can play a full role, while avoiding excessive addition that may have a negative impact on the pet's palatability and nutritional balance.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows: I. This invention, through a unique split-encapsulation design, constructs separate microcapsule systems for the functional active ingredients and probiotics, solving the technical challenge of probiotics being easily damaged by antibacterial components during processing. Specifically, the functional ingredient microcapsules utilize a sodium alginate-calcium chloride-nanozeolite-agar oligosaccharide composite gel network, which not only provides an excellent gastric acid barrier (simulating a 2-hour release rate ≤5% in gastric juice), but also significantly enhances the adsorption capacity and structural stability of the carrier through the high specific surface area of ​​the nanozeolite and the bridging effect of the agar oligosaccharide. The probiotic microcapsules use a sodium alginate-chitosan composite wall material, forming a dense network through polyelectrolyte self-assembly, increasing the gastric acid permeability of probiotics to over 90%. This differentiated protection strategy ensures that the activity retention rate of each component exceeds 85% during processing and storage.

[0015] Second, the dual-targeted release system constructed in this invention achieves time-controlled release of functional components. The functional microcapsules rapidly release ≥50% within 30 minutes under intestinal pH conditions, quickly establishing a deodorizing environment. Meanwhile, the probiotic microcapsules precisely release active probiotics at the posterior end of the intestine through the pH-responsive characteristics of the chitosan layer. This release strategy not only avoids mutual interference between components during delivery but also, through precise control of the release timing, enables probiotics to immediately and rapidly colonize in the established optimized environment, shortening the colonization lag period of traditional methods from 12-24 hours to 4-6 hours, significantly improving the efficiency of action.

[0016] Third, the synergistic deodorization mechanism designed based on the characteristics of each component in this invention forms a complete closed loop for odor control. First, ethyl lactate and phytic acid reduce the generation of malodor precursors at the source by inhibiting protease activity and complexing metal ions. Subsequently, nano-zeolite and yucca extract (containing 45% steroidal saponins), with their large specific surface area and special molecular structure, efficiently adsorb small-molecule odor substances such as ammonia and hydrogen sulfide that have already been generated. At the same time, highly active probiotics rapidly proliferate and occupy ecological niches, fundamentally improving the intestinal microecology through competitive exclusion and metabolic regulation. These three mechanisms are closely linked in time and space, improving deodorization efficiency by more than 3 times compared to single-mechanism products, and extending the duration of action to more than 24 hours. Detailed Implementation

[0017] To enable those skilled in the art to understand the features and effects of this application, the terms and expressions used in the specification and claims are explained and defined in general below. Unless otherwise specified, all technical and scientific terms used herein have the ordinary meaning understood by those skilled in the art in this application, and in case of conflict, the definitions in this specification shall prevail.

[0018] The present application will be described below with reference to specific embodiments and examples. It should be understood that these specific embodiments and examples are merely illustrative and are not intended to limit the scope or use of the present application.

[0019] Unless otherwise stated, the methods, reagents, and conditions used in the preparation examples, comparative examples, and embodiments described below are conventional methods, reagents, and conditions in the art.

[0020] Unless otherwise specified, in this application, parts by weight represent the relative number of mass parts in the composition, which can be any mass unit, such as, but not limited to, kilograms, grams, etc.

[0021] The specific embodiments are described in detail below, but it should be understood that the scope of protection of the present invention is not limited to the specific embodiments. Unless otherwise specified, the raw materials and reagents used in the examples are commercially available.

[0022] Note: Yucca extract is from Xi'an Jincuifang Plant Technology Development Co., Ltd., and contains 45% steroidal saponins, namely yucca saponins.

[0023] Example 1 Preparation steps: 1. Preparation of component A: Take 10 kg of ethyl lactate and 10 kg of maltodextrin, and prepare solutions of 125 g / L and 300 g / L respectively with distilled water. Stir and mix at 400 rpm for 15 minutes at 30℃ to obtain component A.

[0024] 2. Preparation of component B: Take 5 kg of porcine blood protein peptide (molecular weight 600 Da), 2.5 kg of tangerine peel extract (total flavonoid content 25%), 15 kg of monoglyceride and 22.5 kg of rapeseed oil. Dissolve the first three in rapeseed oil at 45℃ and stir until completely homogeneous to obtain component B.

[0025] 3. Preparation of component C: Take 4 kg of yucca extract (containing 45% steroidal saponins) and 2 kg of phytic acid, prepare a 150 g / L solution with distilled water, and mix it with component B at 300 rpm for 10 minutes at 55℃ to obtain component C.

[0026] 4. Preparation of component D: Take 0.6 kg of nano-sized zeolite powder (average particle size 80 nm) and 1.8 kg of agar oligosaccharide (degree of polymerization 5) and dry mix them. Then add 3% of the mass of component C obtained in step (3) to component C and disperse it under 400 W ultrasonic power for 8 minutes to obtain component D.

[0027] 5. Mixing and emulsification: Mix component A and component D at a mass ratio of 1:3 and emulsify at 50°C and a shear rate of 16,000 rpm for 15 minutes to form an emulsion.

[0028] 6. Ionic gelation: Add 4 kg of sodium alginate solution with a mass concentration of 30 g / L (mass ratio of 1:5 to emulsion), stir evenly, and then add dropwise at a rate of 1.5 mL / min to 3 kg of calcium chloride solution with a mass concentration of 40 g / L to form gel microspheres.

[0029] 7. Spray drying: Inlet temperature 170℃, outlet temperature 90℃, atomization pressure 0.3MPa, to obtain microcapsule powder with a moisture content of 4.2%.

[0030] 8. Preparation of probiotic microcapsules: 7.5 kg of Lactobacillus (2 × 10^10 CFU / g viable count) was uniformly dispersed in a sodium alginate solution with a mass concentration of 25 g / L. The microcapsules were formed by high-speed shearing in vegetable oil containing emulsifier, forming W / O type droplets. A calcium chloride acetic acid solution with a mass concentration of 25 g / L was added to initiate an internal gelation reaction. The microcapsules were then treated with a chitosan solution with a mass concentration of 10 g / L for 15 minutes. Finally, the microcapsule powder was obtained by fluidized bed drying.

[0031] 9. Post-processing: The above-mentioned functional microcapsule powder, probiotic microcapsule powder and probiotic fermentation promoter powder (2.5 kg of mannan oligosaccharide and 2.5 kg of fructooligosaccharide) are thoroughly mixed in a mass ratio of 80:10:10. 2 kg of hydroxypropyl methylcellulose binder with a mass fraction of 3% is added, and the mixture is pressed into cakes at 15 MPa.

[0032] Example 2 Preparation steps: 1. Preparation of component A: Take 8 kg of ethyl lactate and 8 kg of maltodextrin, and prepare solutions of 100 g / L and 250 g / L respectively with distilled water. Stir and mix at 300 rpm for 10 minutes at 25℃ to obtain component A.

[0033] 2. Preparation of component B: Take 3 kg of porcine blood protein peptide (molecular weight 500 Da), 1.5 kg of tangerine peel extract (total flavonoid content 20%), 9 kg of monoglyceride and 13.5 kg of rapeseed oil. Dissolve the first three in rapeseed oil at 40℃ and stir until completely homogeneous to obtain component B.

[0034] 3. Preparation of component C: Take 2.4 kg of yucca extract (containing 45% steroidal saponins) and 1.2 kg of phytic acid, prepare a 100 g / L solution with distilled water, and mix it with component B at 200 rpm for 5 minutes at 50℃ to obtain component C.

[0035] 4. Preparation of component D: Take 0.2 kg of nano-sized zeolite powder (average particle size 50 nm) and 0.6 kg of agar oligosaccharide (degree of polymerization 4) and dry mix them. Then add 1% of the mass of component C obtained in step (3) to component C and disperse it under 300 W ultrasonic power for 5 minutes to obtain component D.

[0036] 5. Mixing and emulsification: Mix component A and component D at a mass ratio of 1:3 and emulsify at 45°C and a shear rate of 15,000 rpm for 10 minutes to form an emulsion.

[0037] 6. Ionic gelation: Add 3.2 kg of sodium alginate solution with a mass concentration of 20 g / L (mass ratio of 1:5 to emulsion), stir evenly, and then add dropwise at a rate of 1 mL / min to 2.4 kg of calcium chloride solution with a mass concentration of 30 g / L to form gel microspheres.

[0038] 7. Spray drying: Inlet temperature 160℃, outlet temperature 85℃, atomization pressure 0.2MPa, to obtain microcapsule powder with a moisture content of 4.8%.

[0039] 8. Preparation of probiotic microcapsules: 4.5 kg of Lactobacillus (2 × 10^10 CFU / g viable count) was uniformly dispersed in a sodium alginate solution with a mass concentration of 20 g / L. The solution was then subjected to high-speed shearing in vegetable oil containing emulsifier to form W / O type droplets. A calcium chloride acetic acid solution with a mass concentration of 20 g / L was added to initiate an internal gelation reaction. The microcapsules were then treated with a chitosan solution with a mass concentration of 5 g / L for 10 minutes. Finally, the microcapsule powder was obtained by fluidized bed drying.

[0040] 9. Post-processing: The above-mentioned functional microcapsule powder, probiotic microcapsule powder and probiotic fermentation promoter powder (1.5 kg of mannan oligosaccharide and 1.5 kg of fructooligosaccharide) are thoroughly mixed in a mass ratio of 75:15:10. 1.2 kg of hydroxypropyl methylcellulose binder with a mass fraction of 2% is added, and the mixture is pressed into cakes at 10 MPa.

[0041] Example 3 Preparation steps: 1. Preparation of component A: Take 12 kg of ethyl lactate and 12 kg of maltodextrin, and prepare solutions of 150 g / L and 350 g / L respectively with distilled water. Stir and mix at 35℃ and 500 rpm for 20 minutes to obtain component A.

[0042] 2. Preparation of component B: Take 6 kg of porcine blood protein peptide (molecular weight 800 Da), 3 kg of tangerine peel extract (total flavonoid content 30%), 18 kg of monoglyceride and 27 kg of rapeseed oil. Dissolve the first three in rapeseed oil at 50℃ and stir until completely homogeneous to obtain component B.

[0043] 3. Preparation of component C: Take 4.8 kg of yucca extract (containing 45% steroidal saponins) and 2.4 kg of phytic acid, prepare a 200 g / L solution with distilled water, and mix it with component B at 400 rpm for 15 minutes at 60℃ to obtain component C.

[0044] 4. Preparation of component D: Take 0.8 kg of nano-sized zeolite powder (average particle size 100 nm) and 2.4 kg of agar oligosaccharide (degree of polymerization 6) and dry mix them. Then add 5% of the mass of component C obtained in step (3) to component C and disperse it under 500 W ultrasonic power for 10 minutes to obtain component D.

[0045] 5. Mixing and emulsification: Mix component A and component D at a mass ratio of 1:3 and emulsify at 55°C and a shear rate of 18,000 rpm for 20 minutes to form an emulsion.

[0046] 6. Ionic gelation: Add 4.8 kg of sodium alginate solution with a mass concentration of 40 g / L (mass ratio of 1:5 to emulsion), stir evenly, and then add dropwise at a rate of 2 mL / min to 3.6 kg of calcium chloride solution with a mass concentration of 50 g / L to form gel microspheres.

[0047] 7. Spray drying: Inlet temperature 180℃, outlet temperature 95℃, atomization pressure 0.4MPa, to obtain microcapsule powder with a moisture content of 4.5%.

[0048] 8. Preparation of probiotic microcapsules: 9 kg of Lactobacillus (3 × 10^10 CFU / g viable count) was uniformly dispersed in a sodium alginate solution with a mass concentration of 30 g / L. The microcapsules were formed by high-speed shearing in vegetable oil containing emulsifier, forming W / O type droplets. A calcium chloride acetic acid solution with a mass concentration of 30 g / L was added to initiate an internal gelation reaction. The microcapsules were then treated with a chitosan solution with a mass concentration of 15 g / L for 20 minutes. Finally, the microcapsule powder was obtained by vacuum low-temperature drying.

[0049] 9. Post-processing: The above-mentioned functional microcapsule powder, probiotic microcapsule powder and probiotic fermentation promoter powder (3 kg of mannan oligosaccharide and 3 kg of fructooligosaccharide) are thoroughly mixed in a mass ratio of 85:5:10. 3 kg of hydroxypropyl methylcellulose binder with a mass fraction of 5% is added, and the mixture is pressed into cakes at 20 MPa.

[0050] Comparative Example 1 (Single Microcapsule System) Preparation steps: 1. Preparation of component A: Take 10 kg of ethyl lactate and 10 kg of maltodextrin, and prepare solutions of 125 g / L and 300 g / L respectively with distilled water. Stir and mix at 400 rpm for 15 minutes at 30℃ to obtain component A.

[0051] 2. Preparation of component B: Take 5 kg of porcine blood protein peptide (molecular weight 600 Da), 2.5 kg of tangerine peel extract (total flavonoid content 25%), 15 kg of monoglyceride and 22.5 kg of rapeseed oil. Dissolve the first three in rapeseed oil at 45℃ and stir until completely homogeneous to obtain component B.

[0052] 3. Preparation of component C: Take 4 kg of yucca extract (containing 45% steroidal saponins) and 2 kg of phytic acid, prepare a 150 g / L solution with distilled water, and mix it with component B at 300 rpm for 10 minutes at 55℃ to obtain component C.

[0053] 4. Preparation of component D: Take 0.6 kg of nano-sized zeolite powder (average particle size 80 nm) and 1.8 kg of agar oligosaccharide (degree of polymerization 5) and dry mix them. Then add them to component C at an addition amount of 3% of the total mass of component C. Disperse them under ultrasonic power of 400 W for 8 minutes to obtain component D.

[0054] 5. Mixing and emulsification: Mix component A and component D at a mass ratio of 1:3 and emulsify at 50°C and a shear rate of 16,000 rpm for 15 minutes to form an emulsion.

[0055] 6. Add probiotics: While maintaining the temperature of the emulsion obtained in step 5 at 50°C, add lactobacillus (live count ≥ 1 × 10^10 CFU / g) directly and stir continuously at 200~300 rpm for 5 minutes to ensure that the probiotics and the functional components in the emulsion are fully in contact and exposed to the combined heat and chemical stress environment.

[0056] 7. Ionic gelation: Add 4 kg of sodium alginate solution with a mass concentration of 30 g / L (mass ratio of 1:5 to emulsion), stir evenly, and then add dropwise at a rate of 1.5 mL / min to 3 kg of calcium chloride solution with a mass concentration of 40 g / L to form gel microspheres containing all components.

[0057] 8. Secondary coating treatment: Immerse the wet gel microspheres in a chitosan solution with a mass concentration of 10 g / L for 15 minutes to form sodium alginate-chitosan composite gel microspheres.

[0058] 9. Spray drying: Inlet temperature 170℃, outlet temperature 90℃, atomization pressure 0.3MPa, to obtain microcapsule powder with a moisture content of 5.2%.

[0059] 10. Post-processing: Mix the above microcapsule powder with probiotic fermentation promoter powder (2.5 kg of mannan oligosaccharide and 2.5 kg of fructooligosaccharide) at a mass ratio of 90:10, add 2 kg of hydroxypropyl methylcellulose binder with a mass fraction of 3%, and press into cakes at 15 MPa.

[0060] Comparative Example 2 (without nanomaterial reinforcement) Preparation steps: 1. Preparation of component A: Take 10 kg of ethyl lactate and 10 kg of maltodextrin, and prepare solutions of 125 g / L and 300 g / L respectively with distilled water. Stir and mix at 400 rpm for 15 minutes at 30℃ to obtain component A.

[0061] 2. Preparation of component B: Take 5 kg of porcine blood protein peptide (molecular weight 600 Da), 2.5 kg of tangerine peel extract (total flavonoid content 25%), 15 kg of monoglyceride and 22.5 kg of rapeseed oil. Dissolve the first three in rapeseed oil at 45℃ and stir until completely homogeneous to obtain component B.

[0062] 3. Preparation of component C: Take 4 kg of yucca extract (containing 45% steroidal saponins) and 2 kg of phytic acid, prepare a 150 g / L solution with distilled water, and mix it with component B at 300 rpm for 10 minutes at 55℃ to obtain component C.

[0063] 4. Mixing and Emulsification: Mix component A and component C at a mass ratio of 1:3, and emulsify at 50°C and a shear rate of 16,000 rpm for 15 minutes to form an emulsion. (Note: No nano-zeolite powder or agar oligosaccharides are added.) 5. Ionic gelation: Add 4 kg of sodium alginate solution with a mass concentration of 30 g / L (mass ratio of 1:5 to emulsion), stir evenly, and then add dropwise at a rate of 1.5 mL / min to 3 kg of calcium chloride solution with a mass concentration of 40 g / L to form gel microspheres.

[0064] 6. Spray drying: Inlet temperature 170℃, outlet temperature 90℃, atomization pressure 0.3MPa, to obtain microcapsule powder with a moisture content of 5.8%.

[0065] 7. Preparation of probiotic microcapsules: 7.5 kg of Lactobacillus (2 × 10^10 CFU / g viable count) was uniformly dispersed in a sodium alginate solution with a mass concentration of 25 g / L. The microcapsules were formed by high-speed shearing in vegetable oil containing emulsifier, forming W / O type droplets. A calcium chloride acetic acid solution with a mass concentration of 25 g / L was added to initiate an internal gelation reaction. The microcapsules were then treated with a chitosan solution with a mass concentration of 10 g / L for 15 minutes. Finally, the microcapsule powder was obtained by fluidized bed drying.

[0066] 8. Post-processing: The above-mentioned functional microcapsule powder, probiotic microcapsule powder and probiotic fermentation promoter powder (2.5 kg of mannan oligosaccharide and 2.5 kg of fructooligosaccharide) are thoroughly mixed in a mass ratio of 80:10:10. 2 kg of hydroxypropyl methylcellulose binder with a mass fraction of 3% is added, and the mixture is pressed into cakes at 15 MPa.

[0067] Comparative Example 3 (No prebiotic synergy) Preparation steps: 1. Preparation of component A: Take 10 kg of ethyl lactate and 10 kg of maltodextrin, and prepare solutions of 125 g / L and 300 g / L respectively with distilled water. Stir and mix at 400 rpm for 15 minutes at 30℃ to obtain component A.

[0068] 2. Preparation of component B: Take 5 kg of porcine blood protein peptide (molecular weight 600 Da), 2.5 kg of tangerine peel extract (total flavonoid content 25%), 15 kg of monoglyceride and 22.5 kg of rapeseed oil. Dissolve the first three in rapeseed oil at 45℃ and stir until completely homogeneous to obtain component B.

[0069] 3. Preparation of component C: Take 4 kg of yucca extract (containing 45% steroidal saponins) and 2 kg of phytic acid, prepare a 150 g / L solution with distilled water, and mix it with component B at 300 rpm for 10 minutes at 55℃ to obtain component C.

[0070] 4. Preparation of component D: Take 0.6 kg of nano-sized zeolite powder (average particle size 80 nm) and 1.8 kg of agar oligosaccharide (degree of polymerization 5) and dry mix them. Then add them to component C at an addition amount of 3% of the total mass of component C. Disperse them under ultrasonic power of 400 W for 8 minutes to obtain component D.

[0071] 5. Mixing and emulsification: Mix component A and component D at a mass ratio of 1:3 and emulsify at 50°C and a shear rate of 16,000 rpm for 15 minutes to form an emulsion.

[0072] 6. Ionic gelation: Add 4 kg of sodium alginate solution with a mass concentration of 30 g / L (mass ratio of 1:5 to emulsion), stir evenly, and then add dropwise at a rate of 1.5 mL / min to 3 kg of calcium chloride solution with a mass concentration of 40 g / L to form gel microspheres.

[0073] 7. Spray drying: Inlet temperature 170℃, outlet temperature 90℃, atomization pressure 0.3MPa, to obtain microcapsule powder with a moisture content of 4.3%.

[0074] 8. Preparation of probiotic microcapsules: 7.5 kg of Lactobacillus (2 × 10^10 CFU / g viable count) was uniformly dispersed in a sodium alginate solution with a mass concentration of 25 g / L. The microcapsules were formed by high-speed shearing in vegetable oil containing emulsifier, forming W / O type droplets. A calcium chloride acetic acid solution with a mass concentration of 10 g / L was added to initiate an internal gelation reaction. The microcapsules were then treated with a chitosan solution with a mass concentration of 10 g / L for 15 minutes. Finally, the microcapsule powder was obtained by fluidized bed drying.

[0075] 9. Post-processing: Mix the above functional microcapsule powder and probiotic microcapsule powder thoroughly at a mass ratio of 90:10 (Note: do not add probiotic fermentation promoter powder), add 2 kg of 3% hydroxypropyl methylcellulose binder, and press into cakes at 15 MPa.

[0076] Comparative Example 4 (Traditional electrostatic droplet generation process) Preparation steps: Steps 1 to 7 are exactly the same as in Example 1.

[0077] 8. Preparation of probiotic microcapsules: 7.5 kg of Lactobacillus (2 × 10^10 CFU / g viable count) was uniformly dispersed in a sodium alginate solution with a mass concentration of 25 g / L. Using a traditional electrostatic drop generator, the microcapsules were added dropwise at a flow rate of 20 mL / h to a calcium chloride solution with a mass concentration of 40 g / L under a voltage of 15 kV and a nozzle diameter of 0.8 mm to form primary gel beads. The primary gel beads were then immersed in a chitosan solution with a mass concentration of 10 g / L for 15 minutes. Finally, the microcapsule powder was obtained by fluidized bed drying.

[0078] 9. Post-processing: Same as in Example 1.

[0079] Comparative Example 5 (No separate encapsulation + no nanomaterials + no prebiotics) Preparation steps: 1. Preparation of component A: Take 10 kg of ethyl lactate and 10 kg of maltodextrin, and prepare solutions of 125 g / L and 300 g / L respectively with distilled water. Stir and mix at 400 rpm for 15 minutes at 30℃ to obtain component A.

[0080] 2. Preparation of component B: Take 5 kg of porcine blood protein peptide (molecular weight 600 Da), 2.5 kg of tangerine peel extract (total flavonoid content 25%), 15 kg of monoglyceride and 22.5 kg of rapeseed oil. Dissolve the first three in rapeseed oil at 45℃ and stir until completely homogeneous to obtain component B.

[0081] 3. Preparation of component C: Take 4 kg of yucca extract (containing 45% steroidal saponins) and 2 kg of phytic acid, prepare a 150 g / L solution with distilled water, and mix it with component B at 300 rpm for 10 minutes at 55℃ to obtain component C.

[0082] 4. Mixing and emulsification: Mix component A and component C at a mass ratio of 1:3, add 7.5 kg of lactobacillus (2 × 10^10 CFU / g live bacteria), and emulsify at 50℃ and a shear rate of 16000 rpm for 15 minutes to form an emulsion.

[0083] 5. Ionic gelation: Add 4 kg of sodium alginate solution with a mass concentration of 30 g / L (mass ratio of 1:5 to emulsion), stir evenly, and then add dropwise at a rate of 1.5 mL / min to 3 kg of calcium chloride solution with a mass concentration of 40 g / L to form gel microspheres.

[0084] 6. Spray drying: Inlet temperature 170℃, outlet temperature 90℃, atomization pressure 0.3MPa, to obtain microcapsule powder with a moisture content of 6.2%.

[0085] 7. Post-processing: The above microcapsule powder is directly used, and 2 kg of hydroxypropyl methylcellulose binder with a mass fraction of 3% is added. The mixture is then pressed into cakes at 15 MPa.

[0086] The product performance of Examples 1-3 and Comparative Examples 1-5 was tested using the following methods: 1. Probiotic survival rate test Initial viable count: determined by plate count method according to GB 4789.2 standard. viable cell count after processing: Sampling → Serial dilution → Pour plate → Incubate at 36℃ for 48 h → Count Gastric acid treatment: Simulated gastric juice (pH 2.0, containing pepsin) → Shaking at 37℃ for 2 hours → Neutralization → Viable bacteria count Storage stability: Accelerated test (40℃, RH 75%) → periodic sampling → viable cell count 2. Targeted release performance test In vitro simulated digestion: Gastric juice stage: pH 2.0 buffer solution, shaken at 37°C for 2 hours, with periodic sampling and testing. Intestinal fluid stage: pH 6.8 buffer (containing pancreatic enzymes), shaken at 37°C for 4 hours, with periodic sampling and testing. Release rate determination: The content of active ingredient was detected by HPLC, and the cumulative release rate was calculated. 3. Deodorization effect test In vitro fermentation model: Inoculation with gut microbiota → Addition of substrate → Anaerobic culture at 37°C Gas sampling: headspace sampling → gas chromatography analysis Inhibition rate calculation: (Control group - Experimental group) / Control group × 100% 4. Physical performance testing Mechanical strength: measured by a texture analyzer, compression mode, speed 1 mm / s Particle integrity: Vibrating sieving method, amplitude 2mm, time 10min Moisture content: rapid moisture analyzer, 105℃ to constant weight Dispersion: Evaluation based on the degree of aggregation using the static observation method. 5. Process performance testing Processing capacity: Output per unit time measurement Particle size distribution: Laser particle size analyzer, wet method measurement Energy consumption: Real-time monitoring by electricity meter Process stability: Calculate the standard deviation after 30 consecutive production batches. 6. Economic Analysis Cost accounting: Raw material purchase price + energy consumption in the production process + labor costs Price-performance ratio index: Overall performance score / unit cost All the above tests were repeated 3 times. The data are expressed as mean ± standard deviation. The test results are shown in Tables 1-6. Table 1 Comparison of probiotic survival rates Table 2 Comparison of Targeted Release Performance Table 3 Comparison of deodorization effects Table 4 Comparison of Physical Properties Table 5 Comparison of process performance Table 6 Economic Comparison Based on the data in the table above, we can conclude that: Example 1 demonstrated the best probiotic protection effect, with a survival rate of 94.2% after gastric acid treatment, significantly better than all comparative examples. Comparative example 1 used a single microcapsule system, where probiotics were directly exposed to an emulsion containing functional ingredients such as ethyl lactate and phytic acid before encapsulation, and simultaneously subjected to combined heat and chemical stress, resulting in severe inactivation during subsequent processing and the lowest survival rate (42.3%). This fully confirms the necessity of separate encapsulation for protecting probiotic activity. Comparative example 3 (without prebiotics) showed a significant decrease in long-term storage survival rate (down to 58.4% after 60 days), demonstrating the key role of prebiotics in maintaining bacterial activity. This indicates that separate encapsulation combined with prebiotic synergy are two key factors for achieving high survival rates; the absence of either will lead to a significant decline in performance.

[0087] Example 1 showed a gastric juice protection rate of 96.2% and an intestinal juice release rate of 62.4% after 30 minutes; Comparative Example 1 showed a gastric juice release rate as high as 18.6%, indicating poor protective effect; Comparative Example 2 showed slow intestinal juice release (only 38.7% after 30 minutes), demonstrating the role of nanomaterials in improving the release rate. This indicates that the technical solution of this invention achieves the ideal mode of "near-zero release in the stomach and rapid release in the intestines," and the release curve meets the design requirements.

[0088] Example 1 showed an inhibition rate of over 72% for all four major malodorous substances, demonstrating the best overall deodorization effect. Comparative Example 5 showed inhibition rates below 46% for all substances, proving the limited effectiveness of a single mechanism. Duration of action: Example 1 lasted over 24 hours, while Comparative Example 1 lasted only 8 hours. This indicates that the synergistic effect of multiple deodorization mechanisms increased deodorization efficiency by approximately 3 times and extended the duration of action by 3 times.

[0089] Example 1 exhibited a mechanical strength of 12.5 MPa, a 115% improvement over the worst comparative example 5 (5.8 MPa); excellent moisture control (4.2%) and particle integrity of 95.2%; all examples achieved a dispersibility grade of 1 (excellent). This demonstrates that nanomaterial reinforcement significantly improves the physical stability and performance of the product.

[0090] Example 1 has a processing capacity of 50 kg / h, which is 25 times higher than that of Comparative Example 4 (2 kg / h); its energy consumption is only 8.5 kWh / kg, far lower than that of Comparative Example 4 (35.6 kWh / kg); and its process stability (σ=0.8) is significantly better than all comparative examples. This demonstrates that the emulsification-internal gelation technology is superior to the traditional electrostatic dripping method in terms of efficiency, energy consumption, and stability.

[0091] Example 1 has a comprehensive cost of 241 yuan / kg and a cost-effectiveness index of 1.00 (benchmark); Comparative Example 4 has the highest cost (393 yuan / kg) and a cost-effectiveness index of only 0.38; Comparative Example 5 has the lowest cost but poor performance, with a cost-effectiveness index of only 0.42. This invention achieves reasonable cost control while ensuring excellent performance, and possesses strong market competitiveness.

[0092] In summary, through systematic innovation in split-type encapsulation design, nanomaterial enhancement, and multiple deodorization mechanisms, we have successfully achieved remarkable technical results: increasing the survival rate of probiotics in gastric acid from less than 50% in traditional solutions to over 90%, extending the deodorization duration from 6-8 hours to 24 hours, increasing production efficiency by 25 times, and reducing energy consumption by 76%. At the same time, we have achieved reasonable cost control while ensuring excellent performance, forming a complete technical solution that balances effectiveness, efficiency, and economy. This provides an innovative product with significant competitive advantages in the field of pet excrement odor control.

[0093] It should be understood that the above embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. It should not be considered that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, several simple deductions or substitutions can be made without departing from the concept of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the protection scope of the present invention.

Claims

1. A method for preparing a pet nutritional composition that can reduce the odor of excrement, characterized in that... Includes the following steps: (1) Preparation of component A: Ethyl lactate and maltodextrin were weighed at a mass ratio of 1:1 and respectively prepared into solutions with distilled water. The concentration of the ethyl lactate solution was 100~150 g / L and the concentration of the maltodextrin solution was 250~350 g / L. The two solutions were then stirred and mixed evenly at 25~35℃ at a stirring speed of 300~500 rpm for 10~20 minutes to obtain component A. (2) Preparation of component B: Weigh porcine blood protein peptide (molecular weight ≤1000Da), tangerine peel extract (total flavonoid content ≥20%), monoglyceride and rapeseed oil in a mass ratio of 10:5:30:

45. Dissolve porcine blood protein peptide, tangerine peel extract and monoglyceride in rapeseed oil at 40~50℃ and stir until completely homogeneous to obtain component B; (3) Preparation of component C: Yucca extract (containing 45% steroidal saponins) and phytic acid were mixed at a mass ratio of 2:1 and prepared into a solution with a concentration of 100~200 g / L using distilled water as the aqueous phase. Then, under stirring conditions of 50~60℃ and 200~400 rpm, the aqueous phase was slowly added to component B (oil phase) and stirred continuously for 5~15 minutes to achieve sufficient pre-dispersion in the oil phase, thus obtaining component C in a crude emulsion state; (4) Preparation of component D: Nanoscale zeolite powder and agar oligosaccharide (degree of polymerization of 2~8) are dry mixed at a mass ratio of 1:3 to obtain a mixture. Then, the mixture is slowly added to component C. The amount of the mixture added is 1~5% of the mass of component C finally obtained in step (3). The mixture is dispersed under ultrasonic power of 300~500W for 5~10 minutes to form a uniform premixed system, i.e. component D. (5) Mixing and emulsification: Mix component A and component D at a mass ratio of 1:3, and use a high-shear mixing emulsifier at a speed of 15,000 to 18,000 rpm for 10 to 20 minutes at a temperature of 45 to 55°C to form an emulsion; (6) Ion gelation: Add sodium alginate solution with a mass concentration of 20~40 g / L to the emulsion. The mass ratio of sodium alginate to emulsion is 1:

5. After stirring evenly, add it dropwise to calcium chloride solution with a mass concentration of 30~50 g / L at a dropping rate of 1~2 mL / min to form gel microspheres. (7) Spray drying: The gel microspheres are spray dried at an inlet temperature of 160~180℃ and an outlet temperature of 85~95℃, with an atomization pressure of 0.2~0.4MPa, to obtain functional microcapsule base material with a moisture content ≤5%; (8) Preparation of probiotic microcapsules: Using emulsification-internal gelation technology, Lactobacillus (live count ≥ 1 × 10^9 CFU / g) was uniformly dispersed in a sodium alginate solution with a mass concentration of 20~30 g / L as the aqueous phase; this aqueous phase was added to a vegetable oil phase containing an appropriate amount of emulsifier, and high-speed shearing was used to form W / O type droplets; then a calcium chloride acetic acid solution with a mass concentration of 20~30 g / L was slowly added, and calcium ions diffused into the droplets to initiate an internal gelation reaction; after solid-liquid separation and washing, the wet microspheres were immersed in a chitosan acetic acid solution with a mass concentration of 5~15 g / L and reacted for 10~20 minutes to form sodium alginate-chitosan composite gel microspheres; finally, the probiotic microcapsules were obtained by fluidized bed drying or vacuum low-temperature drying. (9) Post-processing: The functional microcapsule base material obtained in step (7), the probiotic microcapsules obtained in step (8), and the probiotic fermentation promoter powder (which is a mixture of mannan oligosaccharide and fructooligosaccharide in a mass ratio of 1:1) are fully mixed in a mass ratio of (75~85):(5~15):(5~10) and then granulated or pressed. When granulating, 2~5% of the binder hydroxypropyl methylcellulose is added. When pressing, the pressure is 10~20MPa.

2. The method according to claim 1, characterized in that: In step (1), the concentration of ethyl lactate solution is 125 g / L, the concentration of maltodextrin solution is 300 g / L, the mixing temperature is 30℃, the stirring speed is 400 rpm, and the time is 15 minutes.

3. The method according to claim 1, characterized in that: The molecular weight of the porcine blood protein peptide mentioned in step (2) is 500~800 Da, the total flavonoid content of the tangerine peel extract is 25%, and the dissolution temperature is 45℃.

4. The method according to claim 1, characterized in that: In step (3), the mass ratio of yucca extract (containing 45% steroidal saponins) to phytic acid is 2:1, the solution concentration is 150 g / L, the mixing temperature is 55℃, the stirring speed is 300 rpm, and the time is 10 minutes.

5. The method according to claim 1, characterized in that: The average particle size of the nano-sized zeolite powder in step (4) is 50~100nm, the degree of polymerization of the agar oligosaccharide is 4~6, the amount of component D added is 3% of the total mass of the mixture of component C, the ultrasonic dispersion power is 400W, and the time is 8 minutes.

6. The method according to claim 1, characterized in that: The mixing and emulsification in step (5) is carried out at a temperature of 50°C, a shearing speed of 16000 rpm, and a time of 15 minutes.

7. The method according to claim 1, characterized in that: In step (8), the concentration of sodium alginate solution is 20-30 g / L, the concentration of chitosan solution is 8-12 g / L, and the reaction time is 15 minutes.

8. A pet nutritional composition that reduces the odor of excrement, characterized in that: The composition is a solid particle comprising a functional microcapsule base, probiotic microcapsules, and prebiotics. The wall material of the functional microcapsule base is a sodium alginate-calcium chloride gel network, in which nano-zeolite powder and agar oligosaccharides are integrated. Its core material comprises ethyl lactate, porcine blood protein peptide, tangerine peel extract, yucca extract (containing 45% steroidal saponins), and phytic acid. The wall material of the probiotic microcapsules is a sodium alginate-chitosan composite gel, and its core material contains lactobacillus. The prebiotics are a mixture of mannan oligosaccharides and fructooligosaccharides in a 1:1 mass ratio.

9. The application of the pet nutritional composition according to claim 8 in the preparation of pet food, characterized in that: The amount added to the pet food is 0.5% to 5% by weight.

Images