Pet dog epidermis-hair follicle synergistic repair daily ration and preparation method thereof

Abstract

The invention belongs to the technical field of pet nutritional and functional food processing, and particularly relates to a pet dog epidermis-hair follicle synergistic repair daily ration and a preparation method thereof. The daily ration comprises phytosphingosine, N-stearoyl-L-serine, cholesterol, L-lantidine and epsilon-(gamma-glutamyl)-lysine according to a specific proportion, and the phytosphingosine, the N-stearoyl-L-serine and the cholesterol, the L-lantidine and the epsilon-(gamma-glutamyl)-lysine are respectively used as a cuticle lipid reconstruction precursor and a hair keratin directional cross-linking enhancer. The preparation method comprises the following steps: microencapsulating a lipid precursor, mixing the microencapsulated lipid precursor with a cross-linking agent solution and a basic ration, and instantaneously injecting steam at 105-110 DEG C at 48-52 DEG C by adopting a low-temperature pulse granulation process for forming. According to the method, the activity of thermosensitive components can be protected to the maximum extent, the two functional components can synergistically play the roles of repairing skin barriers and strengthening hair structures in vivo, the water content of the skin of the pet dogs is remarkably increased, water loss is reduced, and the breaking strength and luster of hair are enhanced.

Description

Technical Field

[0001] This invention belongs to the field of pet nutrition and functional food processing technology, specifically relating to a pet dog epidermal-hair follicle synergistic repair diet and its preparation method. Background Technology

[0002] The root cause of dry, brittle, and dull pet fur is often attributed to nutritional imbalances or a lack of essential fatty acids. Current technologies primarily focus on supplementing with single ingredients (such as Omega-3, lecithin) or vitamins. However, a long-neglected technical problem in this field is the undiscovered synergistic deterioration mechanism between the structural imbalance of intercellular lipids in the stratum corneum of the pet's epidermis (especially the ratio of ceramides to cholesterol esters) and the unstable state of the disulfide and hydrogen bond networks of hair keratin. Specifically, traditional coat-enhancing ingredients only focus on the hair shaft itself, neglecting the fundamental repair of the "growing soil"—the epidermal microenvironment surrounding the hair follicle. Specifically, an imbalance in the stratum corneum lipid structure (such as a low ceramide ratio) leads to impaired skin barrier function, increased moisture loss, and indirectly affects the nutrient supply to the hair follicle. The unstable keratin structure (disulfide bonds are easily damaged by oxidative stress) makes the hair fragile and prone to breakage, and traditional nutritional supplements cannot directly act on the covalently cross-linked network of hair proteins. The high-temperature process (>80℃) of the existing granulation process not only destroys heat-sensitive lipid precursors, but also causes conformational changes and inactivation of functional proteins / peptides, making it impossible for the two key components mentioned above to maintain synergistic activity in the final product. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a pet dog diet that can simultaneously repair the lipid structure of the epidermal stratum corneum and strengthen the hair keratin network, and a preparation method that can maximize the preservation of the conformation and synergistic effect of the active ingredients.

[0004] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: The preparation method of a pet dog's epidermal-hair follicle synergistic repair diet includes the following steps: S1: Dissolve phytosphingosine, N-stearoyl-L-serine and cholesterol in food-grade ethanol aqueous solution at 45-50℃ and stir to form a homogeneous lipid precursor solution A. The mass ratio of phytosphingosine, N-stearoyl-L-serine to cholesterol is (0.8-1.2):(0.5-0.8):(0.1-0.3). S2: Dissolve L-lanothionine and ε-(γ-glutamyl)-lysine in deionized water and adjust the pH to 5.5-6.0 with acid to form solution B. The mass ratio of L-lanothionine to ε-(γ-glutamyl)-lysine is (1-2):(0.3-0.6). S3: The lipid precursor solution A obtained in S1 is added to an aqueous dispersion containing high amylose and sodium alginate wall material to form a primary emulsion under high-speed shearing. Then, it is homogenized by high-pressure micro-jet to form a nano-emulsion. Finally, the composite microcapsules C containing the lipid precursor are obtained by spray freeze-drying. The inlet air temperature of the spray freeze-drying is ≤60℃ and the cold trap temperature is ≤-45℃. S4: Mix the composite microcapsules C obtained in S3, the solution B obtained in S2, and the basic diet ingredients, add water to adjust the total material moisture to 18-20%, and perform conditioning treatment at 40-45℃. S5: The material conditioned in S4 is fed into a granulator equipped with a cooling jacket. The temperature of the material in the granulation chamber is maintained at 48-52℃ by controlling the flow rate of the cooling medium. Instantaneous saturated steam at 105-110℃ is injected into the material in a pulse manner at the moment of pressing the die. The contact time between the steam and the material is less than 0.5 seconds, and granulation is carried out. S6: The granules obtained after S5 granulation are cooled at low temperature, and then a premix containing vitamins is applied to the surface of the cooled granules by spraying.

[0005] Furthermore, in the above-mentioned method for preparing a diet for the synergistic repair of the skin and hair follicles of pet dogs, in step S3, the pressure of the high-pressure microfluidic homogenization treatment is 120-180 MPa, and the cycle is 1-3 times.

[0006] Furthermore, in the preparation method of the above-mentioned pet dog epidermal-hair follicle synergistic repair diet, in S3, the mass ratio of the high amylose to sodium alginate is (0.8-1.2):1.

[0007] Furthermore, in the above-mentioned method for preparing a diet for the synergistic repair of the skin and hair follicles of pet dogs, in step S5, the linear velocity of the ring die of the granulator is 2.5-3.5 m / s, and the length-to-diameter ratio of the die holes is (7-9):1.

[0008] Furthermore, in the above-mentioned method for preparing a diet for the synergistic repair of the skin and hair follicles of pet dogs, in step S5, the amount of instantaneous saturated steam injected accounts for 2-4% (w / w) of the total mass of the material.

[0009] Furthermore, in the above-mentioned method for preparing a pet dog epidermal-hair follicle synergistic repair diet, in step S6, the low-temperature cooling is achieved by using cold air at 5-15°C in a fluidized bed to reduce the particle temperature to below 30°C within 8 minutes.

[0010] Furthermore, in the preparation method of the above-mentioned pet dog epidermal-hair follicle synergistic repair diet, in S6, the temperature of the fat carrier during spraying is 35-40℃, and the spraying pressure is 0.3-0.5 MPa.

[0011] The beneficial effects of this invention are as follows: the lipid precursor combination directionally replenishes the specific ceramide synthesis raw materials required for epidermal stratum corneum repair, rebuilding the skin barrier from the source; at the same time, the cross-linking enhancer specifically strengthens the covalent bond network of hair keratin, improving the mechanical strength of hair. Both are ingested through diet and act on the epidermis and hair respectively in the body, forming a synergistic repair chain of "strengthening the foundation (skin) - strengthening the trunk (hair)".

[0012] The composite microcapsules effectively isolate the lipid precursors from the sensitivity to oxygen and heat; while the low-temperature pulse granulation process, through the combination of instantaneous high-temperature gelatinization and bonding with continuous low-temperature protection, not only avoids the melting and rupture of the microcapsule wall material, but also protects the active conformation of heat-sensitive crosslinking agents such as L-lanothionine, enabling them to be effectively absorbed in the intestine and perform their physiological functions.

[0013] Feeding trials have shown that the diet of this invention can not only significantly increase skin moisture content and reduce transepidermal water loss (TEWL), but also simultaneously improve hair breakage strength and luster, and improve the regularity of the scale structure on the hair shaft surface, which cannot be achieved by a single hair-enhancing ingredient or traditional processes. Attached Figure Description

[0014] Figure 1 This is a flowchart illustrating the preparation method of the pet dog epidermal-hair follicle synergistic repair diet involved in this invention. Detailed Implementation

[0015] To explain in detail the technical content, objectives, and effects of the present invention, the following description is provided in conjunction with the embodiments and accompanying drawings.

[0016] Please refer to Figure 1 The present invention relates to a method for preparing a diet for the synergistic repair of the epidermis and hair follicles of pet dogs, comprising the following steps: S1: Mix phytosphoprotein, N-stearoyl-L-serine and cholesterol with a purity >95% in a mass ratio of (0.8-1.2):(0.5-0.8):(0.1-0.3), dissolve in food-grade ethanol at 45-50℃, and stir to form a homogeneous lipid precursor solution A; Temperature control is crucial in this step; too high a temperature will cause cholesterol oxidation, while too low a temperature will result in uneven dissolution.

[0017] S2: Dissolve L-lanothionine and ε-(γ-glutamyl)-lysine in deionized water at a mass ratio of (1-2):(0.3-0.6), and adjust the pH to 5.5-6.0 with acid to form solution B; This pH range is crucial for maintaining the solubility of both and preventing charge neutralization precipitation when subsequently mixed with lipid precursors. S3: Solution A obtained in step S1 is added dropwise to an aqueous dispersion of high amylose and sodium alginate under high-speed shearing, and then homogenized by high-pressure micro-jet 1-3 times at 120-180 MPa to form a nanoemulsion; immediately spray freeze-drying is performed with an inlet air temperature ≤60℃ and a cold trap temperature ≤-45℃ to obtain composite microcapsules C encapsulating lipid precursors; This step is crucial for protecting lipid precursors from thermal damage during subsequent processing. S4: Add the microcapsules C obtained in step S3, the solution B obtained in step S2, and the basic diet excluding the premix to the mixer, add water to adjust the total material moisture to 18-20%, and perform low-speed mixing and conditioning at 40-45℃ for 10-20 minutes. This low-temperature conditioning prepares the material for subsequent pulse granulation, avoiding component deactivation caused by preheating; S5: The material after conditioning in step S4 is fed into a ring die granulator equipped with a cooling jacket. The material temperature in the granulation chamber is maintained at 48-52℃ by controlling the flow rate of the cooling medium. The material is pressed with a ring die linear velocity of 2.5-3.5 m / s and a die length-to-diameter ratio of (7-9):1. Saturated steam at 105-110℃ is pulsed and injected at the moment of pressing. The instantaneous contact time between the steam and the material is <0.5 seconds. S6: Immediately feed the granules obtained in step S5 into a 5-15℃ cold air fluidized bed and cool them to below 30℃ within 5 minutes; then spray the premixed material through a fat carrier at ≤35℃; and package the product in a vacuum or nitrogen-filled environment below 25℃.

[0018] Example 1 S1: Weigh 100 g of phytosphingosine and 60 g of N-stearoyl-L-serine, place them in a water bath at 50±2℃, add 5 L of 60% food-grade ethanol solution, and stir until completely dissolved. Slowly add 20 g of cholesterol (97% purity), maintain the temperature at 50±1℃, and stir for 30 minutes to obtain a clear and homogeneous lipid precursor solution A.

[0019] S2: Weigh 150 g of L-lanothionine and 50 g of ε-(γ-glutamyl)-lysine, add them to 40 L of deionized water, and stir to dissolve. Slowly adjust the pH to 5.8±0.1 using 1 mol / L citric acid solution to obtain solution B.

[0020] S3: Weigh 410 g of high amylose and 410 g of sodium alginate, disperse them in 200 L of deionized water at 50±2℃, and stir to form a uniform dispersion. Under high-speed shearing conditions of 10000±500 rpm, slowly add all of solution A obtained in S1 dropwise to this dispersion, with the addition time controlled at 20 minutes. Transfer the resulting primary emulsion to a high-pressure microjet homogenizer and homogenize twice at a pressure of 150±5 MPa. Immediately after homogenization, the nanoemulsion is spray-dried using the following process parameters: inlet air temperature 58±2℃, atomization pressure 0.8 MPa, feed rate 20 L / h, and cold trap temperature -50±2℃. Microcapsules C are obtained with a moisture content ≤5.0% and an average particle size ≤500 nm.

[0021] S4: Weigh 419 kg of dry basal diet ingredients (formula:). Add all microcapsules C obtained in S3 and all solution B obtained in S2 to the basal diet ingredients into a biaxial differential speed mixer. Start mixing and simultaneously spray in deionized water to adjust the total moisture content of the materials to 19.0±0.5%. Mix and condition at low speed for 15 minutes at 43±2℃.

[0022] S5: Convey the conditioned material to a ring die granulator equipped with a cooling jacket (die diameter 3.0 mm, L / D ratio 8:1). Turn on the cooling system, controlling the temperature of the ethylene glycol aqueous solution (40% by mass) in the jacket to 8±1℃ and the flow rate to 30 L / min. Set the ring die linear velocity to 2.8 m / s and the feeding speed to 500 kg / h. Turn on the pulse steam system, instantaneously injecting saturated steam at 105±2℃ into the die pressing zone. The steam injection pressure is 0.6 MPa, the injection frequency is synchronized with the feeding, and the steam addition amount is 3.0% (w / w) of the material mass. Monitor the material temperature in the granulation chamber in real time to 50±2℃, and ensure the steam contact time is ≤0.3 seconds.

[0023] S6: After granulation, the granules are immediately fed into a fluidized bed cooling dryer, where cold air at 12±1℃ and a velocity of 1.2 m / s is introduced for 5 minutes, resulting in an outlet temperature ≤28℃. 4.5 kg of the premix is ​​dissolved in 15 kg of liquid chicken oil at 35±2℃, and then evenly sprayed onto the surface of the cooled granules using a post-spraying system at a pressure of 0.4 MPa, achieving a coverage rate ≥95%. The granules are then transported to a clean packaging workshop at 25±2℃ and packaged using a nitrogen-filled packaging machine. Each bag contains a net weight of 2.5 kg, and the oxygen permeability of the packaging bag is ≤10 cm³. 3 / m 2 24h atm.

[0024] 0- 1- Comparative Example 1 The scheme of Example 1 was adopted, except that phytosphingosine, N-stearoyl-L-serine, and cholesterol were not added in S1. The basal diet ingredients were replenished in equal amounts, and the total mass remained unchanged. The microencapsulation step in S3 was performed only on the high amylose-sodium alginate dispersion (excluding lipid core material).

[0025] Comparative Example 2 The scheme of Example 1 was adopted, except that L-lanothionine and ε-(γ-glutamyl)-lysine were not added in S2. The amount of deionized water was adjusted to 40 L, and the pH was not adjusted. The basal diet ingredients were replenished in equal amounts.

[0026] Comparative Example 3 The scheme of Example 1 is adopted, except that the mass ratio of phytosphingosine, N-stearoyl-L-serine and cholesterol in S1 is changed to 0.3:0.9:0.5 (the total amount remains the same).

[0027] Comparative Example 4 The scheme of Example 1 is adopted, except that the mass ratio of L-lanothionine to ε-(γ-glutamyl)-lysine in S2 is changed to 0.5:1.5 (the total amount remains the same).

[0028] Comparative Example 5 The scheme of Example 1 was adopted, except that S3 was omitted. The lipid precursor solution A obtained in S1 was directly mixed with the basal diet raw materials for subsequent conditioning and granulation.

[0029] Comparative Example 6 The scheme of Example 1 is adopted, except that: instead of using a pulse steam system in S5, saturated steam at 90±2℃ is introduced into the mixer in the conditioning stage of S4 for 3 minutes, and the temperature of the material after conditioning is 85±2℃. No steam is injected in the granulation stage.

[0030] Comparative Example 7 The scheme of Example 1 is adopted, except that: in S5, the cooling jacket system is turned off, the material temperature in the granulation chamber is controlled at 90±2℃, steam is continuously injected, and the contact time is 2 seconds.

[0031] Comparative Example 8 The scheme of Example 1 is adopted, except that the premix is ​​added and mixed together with the lipid precursor and crosslinking agent in S4, and no post-spraying is performed.

[0032] Comparative Example 9 The scheme of Example 1 is adopted, except that in S3, high amylose and sodium alginate are replaced with gelatin and gum arabic (mass ratio 1:1), and the spray drying inlet air temperature is 85°C.

[0033] Comparative Example 10 The scheme of Example 1 is adopted, except that: in S.

[0034] Feeding trial: Animal selection: 120 healthy adult Beagles, aged 12-18 months and weighing 9.5-11.5 kg, were selected, with half males and half females. All dogs were clinically examined and confirmed to be free of skin diseases, parasitic infections, and endocrine system diseases.

[0035] Basic condition assessment: Before the start of the trial (D0), all dogs were scored on their basic coat condition (using a 1-5 point scale, independently evaluated by 3 professional pet groomers and the average score was taken). The selected dogs should score between 2.5 and 3.5 points to ensure that the initial condition is similar and there is room for improvement.

[0036] Group design: 120 dogs were randomly divided into 11 groups: Example 1 group and Comparative Examples 1-10 groups, with 10 dogs in each group. The grouping process used a random number table method to ensure that there were no statistically significant differences in weight, age, sex, and baseline coat score among the groups (P>0.05).

[0037] Housing Environment: All dogs were housed individually in cages conforming to international standards. During the trial, the ambient temperature was maintained at 22±2℃, and the relative humidity at 50±10%, using a 12-hour light / 12-hour dark cycle. Ventilation was provided daily, and the environment was kept quiet and clean.

[0038] Feeding: Each group of dogs had free access to the corresponding experimental diet (Example 1 or Comparative Examples 1-10) and free access to water. Daily food intake was recorded to ensure adequate nutrition. The experimental diet was the sole source of nutrition for each group, and no additional treats or supplements were provided.

[0039] Health monitoring: Observe the dog's mental state, appetite, feces, and skin condition daily, and weigh it weekly. If any health abnormalities occur, have the dog treated by a veterinarian immediately, and decide whether to use a backup dog according to the contingency plan.

[0040] Skin sampling area: On the back of each dog, approximately 10 cm × 10 cm of fur was shaved using pet-specific electric clippers (with sterilized blades) to serve as a common area for all skin function tests. The shaving procedure was performed 24 hours prior to each test to avoid acute irritation to the skin surface.

[0041] Hair samples: At D60, approximately 50 hairs (including the hair root) were randomly plucked from the edge of the shaved area using sterile tweezers for physical property testing. Approximately 20 additional hairs were taken from adjacent areas for morphological observation. Immediately after collection, all samples were placed in labeled sample bags and stored away from light.

[0042] Blood samples: 5 mL of fasting blood was collected from the cephalic vein of the forelimb before morning feeding on day 60. After the blood samples were allowed to stand for 30 minutes, they were centrifuged at 3000 rpm for 10 minutes to separate the serum, aliquoted into EP tubes, and stored at -80°C for subsequent biochemical analysis.

[0043] Skin barrier function measurement: Before any skin test, the dog should acclimatize to the testing environment for at least 30 minutes. The tests should be conducted in the following order, with at least 5 minutes between each measurement point.

[0044] 1. Water content of the stratum corneum (%): Instrument: Corneometer® CM825 (CK GmbH, Germany).

[0045] Method: Place the probe vertically and gently on the skin surface of the test area, maintaining constant pressure until the reading stabilizes. Repeat the measurement three times at non-adjacent locations within the same area, and take the average value as the final reading at that time point. Record the ambient humidity during the measurement.

[0046] 2. Transdermal water loss rate (TEWL, g / h·m) 2 ): Instrument: Tewameter® TM300 (CK GmbH, Germany).

[0047] Method: Place the probe's open chamber vertically on the skin surface and wait for the reading to stabilize (usually 30-60 seconds). Record the TEWL value under stable conditions. Repeat the measurement three times and take the average. The test should be conducted in a windless environment with stable temperature.

[0048] Measurement of physical and morphological parameters of hair: 1. Hair breaking strength (cN): Instrument: Favimat+ Automatic Single Fiber Strength Tester (Textechno GmbH, Germany).

[0049] Method: Fifty hairs were randomly selected and fixed at a distance of 20 mm using a special clamp for the instrument. The stretching speed was set to 5 mm / min, and the test was started until the fiber broke. The maximum breaking force (cN) was recorded. The mean and standard deviation of the 50 hairs were calculated.

[0050] 2. Hair shine (GU, 60°): Instrument: micro-gloss 60° portable gloss meter (BYK-Gardner GmbH, Germany).

[0051] Method: Place the gloss meter's measuring nozzle firmly against the dog's back (non-shaved area) fur, ensuring the hair direction is consistent and the nozzle is fully covered. Repeat the measurement 5 times on the same area and take the average value. Calibrate with a standard plate before use.

[0052] 3. Hair density (roots / cm²) 2 ): Instrument: Dermatoscope (FotoFinder, Germany) equipped with digital analysis software.

[0053] Methods: Magnified images (usually 20x) were taken of a fixed area on the back using a dermatoscope. After importing the images into the software, the number of hair follicle openings within a 1 cm² area was counted manually or automatically. Three images were taken from different non-overlapping areas, and the average was taken.

[0054] 4. Skin integrity score: Instrument: Scanning electron microscope (SEM, Hitachi, Japan).

[0055] Methods: Ten hairs were collected, fixed to the sample stage with conductive adhesive, sputter-coated with gold, and then placed under an electron microscope. The cuticle scale structure in the middle section of the hair shaft was observed at 5000x magnification. Two technicians, unaware of the grouping, independently scored the hairs: 1 point per hair for clear, tightly and regularly arranged scales; 0 points per hair for blurred, damaged, raised, or missing scales. Each hair was scored up to 1 point, with a total score of 0-10 points for all 10 hairs. The average score from the two scorers was taken as the final score.

[0056] Blood biochemical index measurement: 1. Serum ceramide metabolites (nmol / mL): Methods: Liquid chromatography-tandem mass spectrometry (LC-MS / MS) was used.

[0057] Procedure: Take 100 μL of serum, add internal standard (d7-ceramide), and extract using liquid-liquid extraction. Concentrate and reconstitute under nitrogen before injection for analysis. Quantitative analysis is performed using multiple reaction monitoring (MRM). A standard curve is plotted to calculate sample concentration.

[0058] 2. Serum total antioxidant capacity (T-AOC, U / mL): Methods: The ferric ion reducing / antioxidant capacity assay (FRAP method) was used.

[0059] Reagent kit: Use a commercially available FRAP detection kit (such as Beyotime, catalog number S0116).

[0060] Procedure: Strictly follow the kit instructions. Measure absorbance at 593 nm and calculate the antioxidant capacity of the sample based on the standard curve (using Trolox as a standard).

[0061] D0 (baseline): The day the trial begins.

[0062] D60 (Endpoint): Day 60 of the trial.

[0063] Data computation and statistical analysis Improvement rate calculation: For positive indicators such as skin hydration, tensile strength, and luster: Improvement rate (%) = [(D60 value - D0 value) / D0 value] × 100%; For negative indicators such as TEWL: Reduction rate (%) = [(D0 value - D60 value) / D0 value] × 100% For Mao Xiaopi's rating, the absolute score of D60 is used directly.

[0064] All results are expressed as mean ± standard deviation (SD), n=10.

[0065] Statistical analysis: Data analysis was performed using SPSS 26.0 statistical software.

[0066] First, normality tests (Shapiro-Wilk test) and homogeneity of variance tests (Levene test) were performed on each group of data (such as the D60 improvement rate).

[0067] If the parametric test conditions are met, one-way ANOVA is used to compare the differences among the 11 groups.

[0068] If the ANOVA results show a significant difference, then the least significant difference method (LSD method) is used to further compare the pairs of groups.

[0069] If the data do not meet the parametric test conditions, the Kruskal-Wallis H test (non-parametric ANOVA) is used for intergroup comparisons, followed by the Mann-Whitney U test for pairwise comparisons, and the Bonferroni method is used to correct the p-value.

[0070] The significance level was set at P<0.05. In the presentation of results, different superscript letters (such as a, b, c) were used to indicate differences between groups, and the same letter indicated that the difference was not significant (P>0.05).

[0071] Experimental data (improvement rate of D60 compared to D0, mean ± SD, n=10) are shown in Table 1 and Table 2: Table 1 Table 2 Results analysis: Compared with Example 1, Comparative Example 1 showed a significant decrease in the improvement rate of stratum corneum moisture content (+15.2% vs +38.5%), the reduction rate of TEWL (-12.5% ​​vs -32.1%), and the increase rate of serum ceramide metabolites (+8.5% vs +52.3%), indicating that the lipid precursor combination is a key material basis for rebuilding skin barrier function and promoting the in vivo synthesis of ceramides.

[0072] Compared with Example 1, Comparative Example 2 showed a significant decrease in hair breaking strength (+8.7% vs +25.6%), gloss (+18.9% vs +41.3%), and cuticle score (+1.8 vs +4.5), demonstrating that L-lanothionine and ε-(γ-glutamyl)-lysine are the core functional components for enhancing hair mechanical properties and surface integrity.

[0073] Compared with Example 1, Comparative Example 3 showed a significant decrease in skin barrier-related indicators (moisture content, TEWL) and the rate of increase in ceramide metabolites, indicating that the specific ratio of phytosphingosine, N-stearoyl-L-serine and cholesterol is a prerequisite for achieving efficient and targeted ceramide synthesis.

[0074] Compared with Example 1, Comparative Example 4 showed no significant improvement in hair breakage strength and gloss, and a lower cuticle score, indicating that the ratio between the two crosslinking agents directly affects their effect in forming a stable crosslinked structure in the keratin network.

[0075] Compared with Example 1, Comparative Example 5 showed a significant decrease in the improvement rates of various skin and hair indicators, especially ceramide metabolites (+15.2% vs +52.3%) and total antioxidant capacity (+12.3% vs +35.2%), indicating that microencapsulation is crucial for protecting lipid precursors from oxidative and thermal damage and maintaining their bioactivity.

[0076] Compared with Example 1, Comparative Example 6 showed a significantly weaker overall improvement effect on skin and hair, demonstrating that the low-temperature pulse granulation process can more effectively reduce the thermal denaturation and inactivation of heat-sensitive active ingredients compared with traditional continuous steam conditioning.

[0077] Compared with Example 1, Comparative Example 7 showed that the improvement rate of all indicators was close to the baseline level, indicating that the high-temperature process completely destroys the activity of lipid precursors and protein cross-linking agents, resulting in the failure of the synergistic repair mechanism.

[0078] Compared to Example 1, Comparative Example 8 showed a significantly reduced increase in total antioxidant capacity (T-AOC) (+15.2% vs +35.2%), indicating that the post-coating process can effectively avoid heat loss of heat-sensitive nutrients such as vitamins during granulation.

[0079] Compared with Example 1, Comparative Example 9 showed a decrease in the protective effect against lipid precursors, and the increase rate of ceramide metabolites (+35.2% vs +52.3%) and the degree of skin barrier improvement were both lower than those in Example 1, demonstrating that the high amylose-sodium alginate composite wall material has better protective performance against lipid precursors under low temperature drying conditions.

[0080] Compared to Example 1, Comparative Example 10 In summary, this method can maximize the protection of the activity of heat-sensitive components, enabling the two types of functional components to work synergistically in vivo to repair the skin barrier and strengthen the hair structure, significantly increasing the skin moisture content of pet dogs, reducing moisture loss, and enhancing hair breakage strength and shine.

[0081] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent modifications made based on the content of the present invention specification and drawings, or direct or indirect applications in related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A method for preparing a diet for the synergistic repair of the skin and hair follicles in pet dogs, characterized in that, Includes the following steps: S1: Dissolve phytosphingosine, N-stearoyl-L-serine, and cholesterol in food-grade ethanol aqueous solution at 45-50℃ and stir to form a homogeneous lipid precursor solution A. The mass ratio of phytosphingosine, N-stearoyl-L-serine, and cholesterol is (0.8-1.2):(0.5-0.8):(0.1-0.3). S2: Dissolve L-lanothionine and ε-(γ-glutamyl)-lysine in deionized water and adjust the pH to 5.5-6.0 with acid to form solution B. The mass ratio of L-lanothionine to ε-(γ-glutamyl)-lysine is (1-2):(0.3-0.6). S3: The lipid precursor solution A obtained in S1 is added to an aqueous dispersion containing high amylose and sodium alginate wall material to form a primary emulsion under high-speed shearing. Then, it is homogenized by high-pressure micro-jet to form a nano-emulsion. Finally, the composite microcapsules C containing the lipid precursor are obtained by spray freeze-drying. The inlet air temperature of the spray freeze-drying is ≤60℃ and the cold trap temperature is ≤-45℃. S4: Mix the composite microcapsules C obtained in S3, the solution B obtained in S2, and the basic diet ingredients, add water to adjust the total material moisture to 18-20%, and perform conditioning treatment at 40-45℃. S5: The material conditioned in S4 is fed into a granulator equipped with a cooling jacket. The temperature of the material in the granulation chamber is maintained at 48-52℃ by controlling the flow rate of the cooling medium. Instantaneous saturated steam at 105-110℃ is injected into the material in a pulse manner at the moment of pressing the die. The contact time between the steam and the material is less than 0.5 seconds, and granulation is carried out. S6: The granules obtained after S5 granulation are cooled at low temperature, and then a premix containing vitamins is applied to the surface of the cooled granules by spraying.

2. The method for preparing a pet dog epidermal-hair follicle synergistic repair diet according to claim 1, characterized in that, In S3, the pressure of the high-pressure microjet homogenization treatment is 120-180 MPa, and the cycle is 1-3 times.

3. The method for preparing a pet dog epidermal-hair follicle synergistic repair diet according to claim 1, characterized in that, In S3, the mass ratio of the high amylose to sodium alginate is (0.8-1.2):

1.

4. The method for preparing a pet dog epidermal-hair follicle synergistic repair diet according to claim 1, characterized in that, In S5, the ring die linear velocity of the granulator is 2.5-3.5 m / s, and the length-to-diameter ratio of the die hole is (7-9):

1.

5. The method for preparing a pet dog epidermal-hair follicle synergistic repair diet according to claim 1, characterized in that, In S5, the amount of instantaneous saturated steam injected accounts for 2-4% of the total mass of the material.

6. The method for preparing a pet dog epidermal-hair follicle synergistic repair diet according to claim 1, characterized in that, In S6, the low-temperature cooling is achieved by using cold air at 5-15°C in the fluidized bed to reduce the particle temperature to below 30°C within 8 minutes.

7. The method for preparing a pet dog epidermal-hair follicle synergistic repair diet according to claim 1, characterized in that, In S6, the temperature of the grease carrier during spraying is 35-40℃, and the spraying pressure is 0.3-0.5 MPa.

8. The method for preparing a pet dog epidermal-hair follicle synergistic repair diet according to claim 1, characterized in that, In S4, the ratio of composite microcapsules C: solution B: basal diet dry basis ingredients is 1.64:40:419, and the basal diet dry basis ingredients consist of the following ingredients in parts by weight: 15 parts duck meat powder, 10 parts beef powder, 5 parts beef bone powder, 18 parts rice, 13.5 parts corn, 5 parts tapioca starch, 2.5 parts corn starch, 2 parts cheese, 2 parts beet pulp, 2 parts freeze-dried egg yolk, 1 part egg yolk powder, 0.1 part yeast hydrolysate, 0.1 part codonopsis, 0.1 part wolfberry, 0.1 part honeysuckle, 0.1 part cranberry powder, 0.1 part blueberry powder, 0.2 part pear powder, 0.1 part pumpkin powder, 0.1 part marigold; 0.1 part lecithin, 0.3 parts sodium chloride, 0.2 parts potassium chloride, 0.1 part oligosaccharides, 0.1 part mannan oligosaccharides, 0.1 part DL-methionine, 0.1 part L-lysine hydrochloride; In S6, the seasoning components include 10 parts chicken oil, 5 parts freeze-dried chicken floss, 5 parts pet food compound seasoning, and 2 parts hydrolyzed chicken powder by mass ratio; the mass ratio of premix, basic dry base ingredients, and seasoning components is 4.5:419:

15.

9. A pet dog's epidermis-hair follicle synergistic repair diet, characterized in that... The diet is prepared by the method for preparing the pet dog epidermal-hair follicle synergistic repair diet according to any one of claims 1 to 8.

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