A soft granular pet food formulation and method of making the same

Abstract

The application discloses a soft granular pet food formula and a preparation method thereof, and belongs to the technical field of pet food. The formula is composed of high-quality animal protein, puffed grains, fresh meat paste, glycerol, microcapsule oil and fat, and functional additives, and the soft granular pet food with soft texture, complete nutrition and good palatability is prepared through a low-temperature wet puffing and precise moisture control process. The product does not need to be refrigerated, has a shelf life of 6 months, is especially suitable for puppies, old pets and dogs and cats in a special nursing stage, and has the advantages of both dry food convenience and wet food palatability. The soft granular pet food with soft texture, complete nutrition and good palatability is prepared through a low-temperature process and a natural moisture retention system, is especially suitable for puppies, old pets and dogs and cats in a special nursing stage, and has the advantages of both dry food convenience and wet food palatability.

Description

Technical Field

[0001] This invention relates to the field of pet food technology, and in particular to a formula and preparation method of a soft-particle pet food. Background Technology

[0002] Most dry pet food on the market is currently made of hard kibble. While this makes storage convenient, it presents challenges such as chewing difficulties, poor palatability, and insufficient water intake for senior pets, puppies, animals recovering from surgery, or those with sensitive teeth. Wet food (such as canned food), while having a high moisture content and good palatability, is more expensive, has a shorter shelf life, and requires refrigeration after opening, making it inconvenient to use. Semi-moist or soft kibble pet foods that have emerged in recent years often rely on high sugar, high salt, or chemical moisturizers to maintain softness. Long-term consumption of these foods may lead to obesity, kidney strain, or intestinal flora imbalance.

[0003] Furthermore, traditional high-temperature extrusion processes can easily damage heat-sensitive nutrients (such as vitamins, probiotics, and natural antioxidants), affecting product functionality. Therefore, there is an urgent need to develop a soft-particle pet food that combines good texture, high nutrient retention, natural ingredients, and a long shelf life. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention proposes a formula and preparation method for soft-particle pet food. The aim is to provide a formula and low-temperature wet extrusion preparation method for soft-particle pet food that is nutritionally complete, soft in texture, highly palatable, and has a reasonable shelf life, making it particularly suitable for puppies, seniors, or dogs and cats in special physiological stages.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: The formula of the soft pellet pet food of the present invention includes the following components by weight percentage as shown in Table 1: Table 1. Ingredients of a soft-particle pet food

[0006] Based on this formula, the present invention also proposes a method for preparing soft granule pet food, comprising the following steps: Step 1: Raw material pretreatment Rice or brown rice is puffed at low temperature in a puffing machine at 100-120℃ and 14-16% moisture content to fully gelatinize the starch and improve digestibility.

[0007] Fresh meat (chicken breast or fish) is minced by a meat grinder and then homogenized by a colloid mill to produce a fresh meat paste with a solid content of ≥20%.

[0008] Chicken oil or fish oil is processed using microencapsulation technology, with modified starch or maltodextrin as the wall material, and spray-dried to produce microcapsule powder with an encapsulation rate of ≥90%.

[0009] Step 2: Mixing and conditioning Add puffed grains, animal protein powder, starch, fiber source, minerals, vitamins, amino acids and other dry materials into a twin-shaft paddle mixer and mix for 3 to 5 minutes to ensure uniformity.

[0010] Then add fresh meat paste, glycerin, microencapsulated oil, and an appropriate amount of deionized water, and continue mixing for 8-10 minutes to form a uniform wet material. Control the total moisture content of the material between 28% and 32%, which is the optimal plasticizing range for low-temperature puffing.

[0011] Step 3: Low-temperature wet puffing The wet material is fed into the twin-screw cryogenic extruder via a feeder.

[0012] The temperature of the puffing chamber is controlled in stages, with the maximum temperature ≤95℃, preferably 85~92℃.

[0013] The screw speed is 150–250 rpm, and the die diameter is 3.0–5.0 mm.

[0014] The material is extruded under low shear and low temperature conditions to form a soft, porous strip.

[0015] Step 4: Cooling, shaping, and pelletizing The extruded strip immediately enters the air-cooling tunnel, where the air temperature is ≤25℃, and is cooled until the surface is dry and the core temperature is ≤40℃.

[0016] A rotary cutter is used to simultaneously cut the material into cylindrical or pillow-shaped particles with a length of 4–8 mm.

[0017] Step 5: Surface spraying (optional) Spray a natural palatability enhancer solution (such as a 1:1 mixture of yeast extract and fish oil) onto the surface of the granules, with the amount of spraying controlled at 2-4% of the granule weight, to enhance palatability.

[0018] Step 6: Low-temperature drying and moisture control A low-temperature belt dryer is used, with a temperature of 40–45℃ and a drying time of 30–60 minutes. Through online moisture monitoring, the final product's moisture content is precisely controlled within 8–12%.

[0019] Step 7: Packaging After metal detection and sieving, the products are packaged in nitrogen-filled aluminum foil composite stand-up pouches and stored in a light-proof, sealed container.

[0020] The product characteristics of the soft granule pet food prepared by the above method are shown in Table 2 below: Table 2. Product Characteristics of Soft Pellets Pet Food

[0021] Compared with the prior art, the beneficial effects of the present invention are: 1. This invention employs a low-temperature wet puffing technology with a puffing chamber temperature of ≤95℃, which effectively avoids the inactivation of heat-sensitive components such as vitamins, natural antioxidants, and probiotics compared to the traditional high-temperature extrusion process (usually 120-150℃).

[0022] 2. This invention uses glycerin and fresh meat paste to synergistically provide moisturizing properties, avoiding the use of chemical moisturizers such as propylene glycol and sorbitol, or high-sugar, high-salt systems. Glycerin forms a hydrogen bond network with the proteins and polysaccharides in the meat paste, stabilizing the moisture distribution and allowing the product to maintain a soft texture (hardness 0.8–2.0 N) even at 8–12% moisture content. This natural moisturizing system also reduces the risks of obesity, kidney burden, and intestinal flora imbalance.

[0023] 3. This invention's product has low hardness and is easy to chew, making it especially suitable for young pets, senior pets, pets with oral diseases, or pets recovering from surgery. Compared to traditional hard dry food, this product can be swallowed without strong chewing, reducing the risk of aspiration.

[0024] 4. This invention incorporates fructooligosaccharides, mannan oligosaccharides, and thermostable Bacillus subtilis and Enterococcus faecalis to synergistically promote the proliferation of beneficial intestinal bacteria. Prebiotics selectively promote the growth of Bifidobacteria and Lactobacillus, while probiotic metabolism produces short-chain fatty acids, lowering intestinal pH and inhibiting pathogen colonization. Dietary fiber (such as pumpkin powder) provides physical stimulation, promoting intestinal peristalsis. The number of live bacteria at the time of manufacture is ≥1×10⁻⁶. 8 CFU / g remained at 1.5×10 after 6 months. 8 CFU / g.

[0025] 5. This invention uses microcapsules to encapsulate oils (encapsulation rate ≥90%), and the wall material physically isolates oxygen, delaying fat oxidation. Rosemary extract is rich in phenolic compounds such as rosmarinic acid and salicylic acid, which scavenge free radicals. Citric acid synergistically chelates metal ions, inhibiting oxidation reactions. After 6 months of storage, the peroxide value is only 2.1 meq / kg. Nitrogen-filled packaging further reduces the risk of oxidation, ensuring a shelf life of 6 months at room temperature.

[0026] 6. The present invention has a wide process parameter window (expansion temperature 85-95℃, material moisture content 28-32%, drying temperature 40-45℃), good equipment compatibility, and lower energy consumption than traditional high-temperature processes. The low-temperature drying stage effectively avoids surface hardening of the product, while precisely controlling the moisture content to 8-12%, balancing softness and microbial stability.

[0027] 7. This invention's product requires no refrigeration, is ready to eat straight from the bag, has a long shelf life, and is easy to store and carry. The synergistic effect of fresh meat paste and natural palatability enhancers gives the product a rich, wet-food-like flavor. In palatability tests, the ratio of food intake for dogs and cats was higher than 2:1, superior to ordinary dry food. At the same time, its moderate moisture content can supplement pets' daily water intake and reduce the risk of urinary tract diseases. Detailed Implementation

[0028] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0029] Experimental Design: The following experiments all used the following preparation process: A method for preparing soft granule pet food, including the following steps: Step 1: Raw material pretreatment Rice or brown rice is puffed at low temperature in a puffing machine at 100-120℃ and with a moisture content of 14-16% to fully gelatinize the starch and improve digestibility.

[0030] Fresh meat (chicken breast or fish) is minced by a meat grinder and then homogenized by a colloid mill to produce a fresh meat paste with a solid content of ≥20%.

[0031] Chicken oil or fish oil is processed using microencapsulation technology, with modified starch or maltodextrin as the wall material, and spray-dried to produce microcapsule powder with an encapsulation rate of ≥90%.

[0032] Step 2: Mixing and conditioning Add puffed grains, animal protein powder, starch, fiber source, minerals, vitamins, amino acids and other dry materials into a twin-shaft paddle mixer and mix for 3 to 5 minutes to ensure uniformity.

[0033] Then add fresh meat paste, glycerin, microencapsulated oil, and an appropriate amount of deionized water, and continue mixing for 8-10 minutes to form a uniform wet material. Control the total moisture content of the material between 28% and 32%, which is the optimal plasticizing range for low-temperature puffing.

[0034] Step 3: Low-temperature wet puffing The wet material is fed into the twin-screw cryogenic extruder via a feeder.

[0035] The temperature of the puffing chamber is controlled in stages, with the maximum temperature ≤95℃, preferably 85~92℃.

[0036] The screw speed is 150–250 rpm, and the die diameter is 3.0–5.0 mm.

[0037] The material is extruded under low shear and low temperature conditions to form a soft, porous strip.

[0038] Step 4: Cooling, shaping, and pelletizing The extruded strip immediately enters the air-cooling tunnel, where the air temperature is ≤25℃, and is cooled until the surface is dry and the core temperature is ≤40℃.

[0039] A rotary cutter is used to simultaneously cut the material into cylindrical or pillow-shaped particles with a length of 4–8 mm.

[0040] Step 5: Surface spraying (optional) Spray a natural palatability enhancer solution (such as a 1:1 mixture of yeast extract and fish oil) onto the surface of the granules, with the amount of spraying controlled at 2-4% of the granule weight, to enhance palatability.

[0041] Step 6: Low-temperature drying and moisture control A low-temperature belt dryer is used, with a temperature of 40–45℃ and a drying time of 30–60 minutes. Through online moisture monitoring, the final product's moisture content is precisely controlled within 8–12%.

[0042] Step 7: Packaging After metal detection and sieving, the products are packaged in nitrogen-filled aluminum foil composite stand-up pouches and stored in a light-proof, sealed container.

[0043] Based on the above preparation process, the following examples and comparative examples with different formulations were designed: Example 1 (Preferred Scope): Prepared according to the preferred embodiment formulation, with the following key parameters: Animal protein source: 30 kg of chicken meal; Puffed brown rice: 20 kg; Potato starch: 10 kg; Glycerin: 4.5 kg; Chicken oil microcapsules: 6 kg; Fresh chicken paste: 8 kg; Dietary fiber source: 5 kg of pumpkin powder; Expansion temperature: 90℃; Material moisture content: 30%; Final moisture content: 10%.

[0044] Example 2 (Upper Limit): Animal protein source: 40 kg of fish meal; Puffed rice: 15 kg; Tapioca starch: 15 kg; Glycerin: 6 kg; Fish oil microcapsules: 8 kg; Fresh fish paste: 12 kg; Dietary fiber source: 7 kg of beet pulp; Expansion temperature: 95℃; Moisture content of the material: 32%; Final moisture content: 12%; The remaining parameters and process steps are the same as in Example 1.

[0045] Example 3 (Lower Limit Range): Animal protein source: 25 kg of beef meal; Puffed brown rice: 25 kg; Potato starch: 8 kg; Glycerin: 3 kg; Chicken oil microcapsules: 4 kg; Fresh beef paste: 5 kg; Dietary fiber source: 3 kg of carrot powder; Expansion temperature: 85℃; Material moisture content: 28%; Final moisture content: 8%; The remaining parameters and process steps are the same as in Example 1.

[0046] Comparative Example 1 (High Expansion Temperature): Same as Example 1, but the puffing temperature is set to 120°C (outside the scope of this invention).

[0047] Comparative Example 2 (low glycerol content): Same as Example 1, but with a glycerol content of 1% (below the scope of this invention).

[0048] Comparative Example 3 (High Final Moisture): Same as Example 1, but with a final moisture content of 15% (outside the scope of this invention).

[0049] Comparative Example 4 (Oil without Microencapsulation): Same as in Example 1, but using regular chicken fat instead of microcapsule chicken fat.

[0050] Comparative Example 5 (without probiotics): Same as Example 1, but without the addition of probiotics.

[0051] The product tests for Examples 1-3 and Comparative Examples 1-5 are as follows: 1. Texture property testing (hardness) Method: The particles were compressed using a texture analyzer (TA.XT Plus) with a P / 36R probe and a test speed of 1 mm / s.

[0052] Table 3. Particle texture test

[0053] Table 3 shows that excessively high puffing temperatures lead to excessive starch gelatinization and Maillard reaction, resulting in severe protein denaturation, denser structure, and increased hardness. Glycerol, as a humectant, forms a hydrogen bond network with water, reducing water activity and maintaining the flexible structure of proteins; insufficient glycerol causes rapid water migration and loss, leading to particle hardening. Excessive moisture content, on the other hand, damages the integrity of the particle structure.

[0054] 2. Pepsin digestibility test The test results, conducted according to the method in GB / T 17811-2008, are shown below: Table 4. Pepsin digestibility test

[0055] Table 4 shows that high-temperature treatment leads to protein denaturation and aggregation, masking enzymatic hydrolysis sites and reducing digestibility. Under conditions of moderate glycerol and moisture, proteins maintain moderate denaturation, resulting in more complete enzymatic hydrolysis.

[0056] 3. Probiotic survival rate test The viable bacterial count was determined using the plate count method at the time of manufacture and after 6 months of storage. The results are shown below: Table 4. Probiotic survival rate test

[0057] As shown in Table 5, high temperature (120℃) causes a large number of probiotics to die. The low-temperature puffing (≤95℃) of this invention effectively protects heat-sensitive probiotics, while the natural preservative system and low water activity work together to maintain storage stability.

[0058] 4. Oxidative stability test of oils and fats (peroxide value) Tested according to the method of GB 5009.227-2016, and tested after 6 months of storage, the results are as follows: Table 6. Oil Oxidation Stability Test

[0059] As shown in Table 6, microencapsulated oils significantly delay contact between oils and oxygen through physical isolation via the wall material, and phenolic compounds in rosemary extract scavenge free radicals and synergistically provide antioxidant protection.

[0060] 5. Palatability test (two-basin method) Methods: Thirty adult dogs / cats were selected and fed Example 1 and Comparative Example 2 respectively. The first-time feeding rate and feed intake ratio were recorded.

[0061] Table 7. Palatability Test

[0062] As shown in Table 7, insufficient glycerol leads to dry and hard particles, affecting the taste; the synergistic effect of fresh meat paste and natural palatability enhances palatability significantly.

[0063] 6. Shelf life test Methods: The products were stored at 25℃ and 60% relative humidity for 6 months, and microbial indicators and sensory changes were monitored.

[0064] Table 8. Shelf life test

[0065] As shown in Table 8, a moisture content of ≤12% can effectively inhibit the growth of microorganisms. The natural preservative system (rosemary extract + citric acid) inhibits bacteria synergistically by disrupting cell membrane permeability and lowering pH.

[0066] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A formula for soft-particle pet food, characterized in that, By weight percentage, it contains: 25-40% animal protein source, 15-25% puffed cereal, 8-15% starch, 3-6% glycerol, 4-8% microencapsulated oil, 5-12% fresh meat paste, 3-7% dietary fiber source, 0.05-0.2% taurine, 0.1-0.3% methionine, 0.2-0.5% lysine, 0.1-0.25% vitamin premix, 0.1-0.2% trace element premix, 1-3% natural palatability enhancer, 0.5-1.5% prebiotics, 0.05-0.15% probiotics, and 0.1-0.3% natural preservatives. The final product has a moisture content of 8-12%.

2. The formulation according to claim 1, characterized in that, The animal protein source is selected from one or more of chicken meal, fish meal, and beef meal; The puffed grain is puffed rice or puffed brown rice; The starch is potato starch or cassava starch.

3. The formulation according to claim 1, characterized in that, The microcapsule oil is prepared by encapsulating chicken oil or fish oil with modified starch, with an encapsulation rate of ≥90%.

4. The formulation according to claim 1, characterized in that, The dietary fiber source is selected from one or more of carrot powder, pumpkin powder, and beet pulp; The prebiotic is fructooligosaccharide and / or mannan oligosaccharide.

5. The formulation according to claim 1, characterized in that, The probiotics are heat-resistant Bacillus subtilis and / or Enterococcus faecalis, with a viable count at the time of manufacture ≥1×10⁻⁶. 8 CFU / g.

6. The formulation according to claim 1, characterized in that, The natural preservative is a combination of rosemary extract and citric acid.

7. A method for preparing soft granule pet food, using the formula as described in any one of claims 1 to 6, characterized in that, Includes the following steps: (1) Raw material pretreatment: Grains are puffed at low temperature, fresh meat is made into meat paste, and oil is microencapsulated; (2) Mixing and conditioning: After mixing the dry materials, add fresh meat paste, glycerin, microcapsule oil and water, and control the moisture content of the materials to 28-32%; (3) Low-temperature wet puffing: extrusion molding at a puffing temperature ≤95℃; (4) Cooling and pelletizing: Air-cooled to a center temperature ≤40℃, then simultaneously pelletized; (5) Low-temperature drying: Dry at 40-45℃ until the moisture content is 8-12%; (6) Nitrogen-filled packaging.

8. The preparation method according to claim 7, characterized in that, In step (3), the puffing temperature is 85-92℃, the screw speed is 150-250 rpm, and the die diameter is 3.0-5.0 mm.

9. The preparation method according to claim 7, characterized in that, The step of drying (5) also includes spraying a natural palatability enhancer onto the surface.

10. A soft granule pet food prepared by the preparation method according to any one of claims 7-9, characterized in that, Its particle hardness is 0.8–2.0 N, and its pepsin digestibility is ≥88%.

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