A preparation method for improving the center curing degree of low-temperature baking dog food and a product thereof

Abstract

The application provides a preparation method for improving the center curing degree of low-temperature baked dog food and a product thereof, and belongs to the technical field of pet food. The method comprises the following steps: S1, mixing dog food raw materials to obtain a mixture; the dog food raw materials comprise animal-derived protein materials, plant-derived protein materials and starch raw materials; S2, adding a complex enzyme preparation to the mixture for enzymolysis treatment to obtain an enzymolysis product; the complex enzyme preparation comprises amylase, protease, phytase and non-starch polysaccharide enzyme; S3, performing enzyme inactivation, flash concentration and extrusion molding treatment on the enzymolysis product to obtain dog food granule green bodies; and S4, performing baking treatment on the dog food granule green bodies under a temperature condition lower than 80 DEG C to obtain center-cured low-temperature baked dog food. The application significantly improves the center curing degree of low-temperature baked dog food through enzymolysis treatment of the complex enzyme preparation, and effectively solves the technical problem of outer curing and inner rawness in the low-temperature baking method.

Description

Technical Field

[0001] This invention belongs to the field of pet food technology, and in particular relates to a preparation method and product for improving the center ripeness of low-temperature baked dog food. Background Technology

[0002] With the rapid development of the pet economy and pet owners' increasing focus on pet health, the pet food industry is undergoing a transformation from "satisfaction-oriented" to "nutritional and functional" products. As monogastric animals, dogs and cats have limited digestive capacity for starchy foods and have specific requirements for protein and minerals. Therefore, improving the digestibility and absorption rate of pet food, retaining heat-sensitive nutrients, and improving gut health have become hot research topics for those in the field.

[0003] Currently, commercially available pet dry food is mainly produced using high-temperature extrusion puffing. This method involves cooking, extruding, and pelleting the mixed ingredients under high temperature (120-150℃) and high pressure (3-5MPa). However, high-temperature puffing has the following inherent drawbacks: First, high temperatures can destroy heat-sensitive nutrients, such as vitamins B1, A, and E, as well as some enzymes and probiotics, resulting in the actual measured content of nutrients being far lower than the amount added in the formula. Second, high temperatures cause excessive gelatinization of starch, which easily retrogrades after the product cools, forming resistant starch and reducing digestibility. Third, high temperatures cause excessive Maillard reactions in proteins, destroying some essential amino acids such as lysine and reducing protein bioavailability. Fourth, the surface of the product pellets often needs to be coated with a large amount of oil to improve palatability, leading to problems such as greasy surface, easy oxidation and rancidity, and oil leakage from the packaging.

[0004] In response to the aforementioned drawbacks of high-temperature puffing methods, the industry has recently shifted its focus to the research and application of low-temperature baking methods. Low-temperature baking typically involves prolonged baking at temperatures below 100°C, significantly reducing the loss of heat-sensitive nutrients, resulting in a clean, non-greasy surface and a crisp texture. However, low-temperature baking faces a long-standing technical challenge: due to the low baking temperature, heat transfer to the interior of the particles is slow, leading to incomplete gelatinization of the starch in the center of the particles (gelatinization degree is typically below 80%), resulting in a noticeable "cooked on the outside, raw on the inside" phenomenon. Products with an undercooked core not only have a poor taste, but more seriously, the insufficiently gelatinized starch (i.e., resistant starch) cannot be digested and absorbed by dogs and cats. Once in the lower intestines, it is easily fermented and utilized by harmful bacteria, producing gas and toxins, causing intestinal problems such as bloating, soft stools, and diarrhea. Summary of the Invention

[0005] To address the above technical problems, this invention provides a method for preparing low-temperature baked dog food with improved center ripeness and the resulting product, as detailed below:

[0006] A method for improving the center maturity of low-temperature baked dog food includes the following steps:

[0007] S1. Mix the dog food base to obtain a mixture; the dog food base includes animal-derived protein materials, plant-derived protein materials, and starchy raw materials;

[0008] S2. Add a compound enzyme preparation to the mixture and perform enzymatic hydrolysis to obtain the enzymatic hydrolysis product; the compound enzyme preparation contains amylase, protease, phytase and non-starch polysaccharide enzyme; the mass ratio of amylase, protease, phytase and non-starch polysaccharide enzyme is 3-5:3-5:0.3-0.6:1-2;

[0009] S3. The enzymatic hydrolysis product is subjected to enzyme inactivation, flash evaporation concentration, and extrusion molding to obtain dog food pellet raw material;

[0010] S4. The raw dog food pellets are baked with oil and functional additives at a temperature below 80°C to obtain low-temperature baked dog food with central maturation.

[0011] Furthermore, the amylase is selected from at least one of α-amylase and maltose amylase;

[0012] The protease is selected from at least one of papain and flavor protease;

[0013] The non-starch polysaccharide enzyme is selected from at least one of xylanase, cellulase, and β-glucanase;

[0014] The phytase is a food-grade phytase.

[0015] Furthermore, the weight proportions of each component in the compound enzyme preparation are as follows: 3-5 parts amylase, 3-5 parts protease, 0.3-0.6 parts phytase, and 1-2 parts non-starch polysaccharide enzyme.

[0016] Furthermore, the enzymatic hydrolysis treatment method conditions are as follows: temperature 40-55℃, pH value 6.0-7.0, hydrolysis time 40-50 minutes, and water-to-material ratio of 30-50:1 during hydrolysis.

[0017] Furthermore, the baking temperature is 60-80℃, the baking time is 3-5 hours, and the center gelatinization degree of the baked dog food is ≥90%.

[0018] Furthermore, prior to enzymatic hydrolysis, the mixture is further subjected to crushing and sieving to control the particle size of the material to 60-80 mesh.

[0019] Furthermore, the amount of each combination added during the preparation process, by weight, is as follows:

[0020] Animal-derived protein materials: 40-50 portions;

[0021] Plant-derived protein materials: 15-20 parts;

[0022] Starchy ingredients: 30-40 parts;

[0023] Compound enzyme preparation: 0.5-1.2 parts;

[0024] Oils: 7-12 parts;

[0025] Functional additives: 0.5-0.8 parts.

[0026] Furthermore, the animal-derived protein material is selected from at least one of chicken, duck, fish, and beef;

[0027] The plant-derived protein material is selected from at least one of pea protein, soy protein isolate, and rice protein powder;

[0028] The starchy raw material is selected from at least one of potato, cassava, sweet potato, purple sweet potato, oat, rice, corn, and wheat, and the starchy raw material is pregelatinized (mixed with hot water) before use, with a pregelatinization degree of 30%-50%.

[0029] The functional additives include at least one of prebiotics, vitamins, and mineral ingredients.

[0030] On the other hand, the present invention provides low-temperature baked dog food prepared by the method described above. Figure 1 (by weight, it includes the following components:)

[0031] Animal-derived protein materials: 40-50 portions;

[0032] Plant-derived protein materials: 15-20 parts;

[0033] Starchy ingredients: 30-40 parts;

[0034] Compound enzyme preparation: 0.5-1.2 parts;

[0035] Oils: 7-12 parts;

[0036] Functional additives: 0.5-0.8 parts.

[0037] Furthermore, by weight, it includes the following components:

[0038] Animal-derived protein materials: 45 portions;

[0039] Plant-derived protein materials: 18 portions;

[0040] Starchy raw materials: 35 parts;

[0041] Compound enzyme preparation: 0.8 parts;

[0042] Oil: 10 parts;

[0043] Functional additives: 0.6 parts.

[0044] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0045] 1. This invention significantly improves the center maturation degree of low-temperature baked dog food by adding a compound enzyme preparation for enzymatic hydrolysis, effectively solving the technical problem of the outside being cooked and the inside being raw in low-temperature baking methods. At the same time, it also shortens the time required for the center temperature of the dog food pellets to reach the gelatinization temperature. Experiments show that the center gelatinization degree of the experimental group of this invention reaches 93.8%, which is significantly higher than that of the control group 2-4 without the addition of enzyme preparation. The time required for the center temperature of the experimental group to reach 80℃ (92 minutes) is significantly shorter than that of the control group 2-4, thus improving production efficiency.

[0046] 2. The dog food prepared by this invention has moderate hardness and good crispness, which is significantly lower than that of dog food prepared by high-temperature extrusion method, thus improving the taste and palatability of the product. At the same time, the surface oil condition is significantly improved, with the number and diameter of oil halos being smaller than those of the high-temperature extrusion group. The product surface is clean and non-greasy, reducing problems such as oil leakage in packaging.

[0047] 3. This invention can reduce the loss of heat-sensitive nutrients, such as vitamins, enzymes, and probiotics. Furthermore, the enzymatic hydrolysis process improves the digestibility and absorption rate of nutrients, avoiding nutrient destruction and excessive Maillard reaction of proteins caused by high temperatures in high-temperature puffing methods. This preserves more nutrients and improves the nutritional value of the product. Moreover, the enzymatic hydrolysis process destroys the dense structure and viscous fiber network of proteins, reducing the formation of resistant starch, making starch easier for dogs and cats to digest and absorb. This helps reduce intestinal problems in dogs and cats caused by consuming insufficiently gelatinized starch.

[0048] 4. This invention utilizes a combination of amylase, protease, phytase, and non-starch polysaccharide enzymes. Amylase breaks down some long starch chains, generating dextrin and oligosaccharides, thus lowering the activation energy required for starch gelatinization and making starch easier to gelatinize at low temperatures. Protease breaks down large protein molecules into small peptides and amino acids, disrupting the dense protein network structure. This opens up heat conduction channels and pre-digests the protein, improving subsequent digestibility and absorption. Phytase breaks down phytic acid in starchy raw materials, releasing chelated minerals such as calcium, phosphorus, and zinc. This not only improves the bioavailability of minerals but also reduces the hindering effect of phytic acid-protein-starch complexes on heat transfer. Non-starch polysaccharide enzymes break down the viscous fibrous network in plant cell walls, degrading it into oligosaccharides. This reduces material viscosity, opens up heat transfer channels, and the resulting oligosaccharides can be used as prebiotics by beneficial gut bacteria. The synergistic effect of these four enzymes solves the technical problem of undercooked centers in low-temperature baking, improving baking efficiency and product quality.

[0049] 5. The compound enzyme preparation added in this invention has an enzyme ratio of amylase:protease:phytase:non-starch polysaccharide enzyme = 3-5:3-5:0.3-0.6:1-2. Experimental results show that when the ratio of the four enzymes is different (control group 4-7), the center gelatinization degree is 85.8%-87.2% and the hardness is 160-166N, both of which are inferior to the experimental group (93.8%, 151N). When any one enzyme is missing (control group 8-11), the center gelatinization degree is 80.5%-85.2% and the hardness is 167-175N, with the center gelatinization degree and hardness further decreasing. The effect is worst when amylase or protease is missing, with a center gelatinization degree ≤81.2% and a hardness ≥173N. This proves the importance of amylase, protease, phytase, non-starch polysaccharide enzyme and their ratio in solving the problem of center ripening in low-temperature baking. Attached Figure Description

[0050] Figure 1 Photograph of the low-temperature baked dog food prepared for this invention. Detailed Implementation

[0051] Example 1

[0052] A method for improving the center maturity of low-temperature baked dog food includes the following steps:

[0053] S1. Mix the dog food base to obtain a mixture; the dog food base includes animal-derived protein materials, plant-derived protein materials, and starchy raw materials;

[0054] S2. Add a compound enzyme preparation to the mixture and perform enzymatic hydrolysis to obtain the enzymatic hydrolysis product; the compound enzyme preparation contains amylase, protease, phytase and non-starch polysaccharide enzyme; the mass ratio of amylase, protease, phytase and non-starch polysaccharide enzyme is 3:3:0.3:1;

[0055] S3. The enzymatic hydrolysis product is subjected to enzyme inactivation, flash evaporation concentration, and extrusion molding to obtain dog food pellet raw material;

[0056] S4. The raw dog food pellets are baked at a temperature below 80°C to obtain low-temperature baked dog food with a centrally matured texture.

[0057] Preferably, the amylase is α-amylase;

[0058] The protease is papain;

[0059] The non-starch polysaccharide enzyme is xylanase;

[0060] The phytase is a food-grade phytase.

[0061] Preferably, the weight proportions of each component in the compound enzyme preparation are: 3 parts amylase, 3 parts protease, 0.3 parts phytase, and 1 part non-starch polysaccharide enzyme.

[0062] Preferably, the enzymatic hydrolysis treatment method conditions are: temperature 40℃, pH value 6.0, enzymatic hydrolysis time 40 minutes, and water-to-material ratio of 30:1 during enzymatic hydrolysis. The specific enzymatic hydrolysis method is as follows: take an enzymatic hydrolysis tank, add materials and water, place it in a water bath, and carry out enzymatic hydrolysis under the conditions described above.

[0063] Preferably, the baking temperature is 70°C and the baking time is 3 hours.

[0064] Preferably, before enzymatic hydrolysis, the mixture is further subjected to crushing and sieving to control the particle size of the material to 60 mesh.

[0065] Furthermore, the amount of each combination added during the preparation process, by weight, is as follows:

[0066] Animal-derived protein materials: 40 portions;

[0067] Plant-derived protein materials: 15 portions;

[0068] Starchy ingredients: 30 parts;

[0069] Compound enzyme preparation: 0.5 parts;

[0070] Oils: 7 parts;

[0071] Functional additives: 0.5 parts.

[0072] Furthermore, the animal-derived protein material is selected from chicken, duck, fish, and beef;

[0073] The plant-derived protein materials are selected from pea protein, soy protein isolate, and rice protein powder;

[0074] The starchy raw material is selected from potatoes, cassava, sweet potatoes, purple sweet potatoes, oats, rice, corn, and wheat, and the starchy raw material is pregelatinized before use, with a pregelatinization degree of 30%.

[0075] The functional additives include prebiotics, vitamins, and mineral ingredients.

[0076] Example 2

[0077] A method for improving the center maturity of low-temperature baked dog food includes the following steps:

[0078] S1. Mix the dog food base to obtain a mixture; the dog food base includes animal-derived protein materials, plant-derived protein materials, and starchy raw materials;

[0079] S2. Add a compound enzyme preparation to the mixture and perform enzymatic hydrolysis to obtain the enzymatic hydrolysis product; the compound enzyme preparation contains amylase, protease, phytase and non-starch polysaccharide enzyme; the mass ratio of amylase, protease, phytase and non-starch polysaccharide enzyme is 5:5:0.6:2.

[0080] S3. The enzymatic hydrolysis product is subjected to enzyme inactivation, flash evaporation concentration, and extrusion molding to obtain dog food pellet raw material;

[0081] S4. The raw dog food pellets are baked at a temperature below 80°C to obtain low-temperature baked dog food with a centrally matured texture.

[0082] Preferably, the amylase is maltose amylase;

[0083] The protease is a flavor protease;

[0084] The non-starch polysaccharide enzyme is a cellulase;

[0085] The phytase is a food-grade phytase.

[0086] Preferably, the weight proportions of each component in the compound enzyme preparation are: 5 parts amylase, 5 parts protease, 0.6 parts phytase, and 2 parts non-starch polysaccharide enzyme.

[0087] Preferably, the enzymatic hydrolysis treatment method conditions are: temperature 55℃, pH value 7.0, enzymatic hydrolysis time 50 minutes, and water-to-material ratio of 50:1 during enzymatic hydrolysis.

[0088] Preferably, the baking temperature is 80°C and the baking time is 5 hours.

[0089] Preferably, before enzymatic hydrolysis, the mixture is further subjected to crushing and sieving to control the particle size of the material to 80 mesh.

[0090] Furthermore, the amount of each combination added during the preparation process, by weight, is as follows:

[0091] Animal-derived protein materials: 50 portions;

[0092] Plant-derived protein materials: 20 portions;

[0093] Starchy raw materials: 40 parts;

[0094] Compound enzyme preparation: 1.2 parts;

[0095] Oil: 12 parts;

[0096] Functional additives: 0.8 parts.

[0097] Furthermore, the animal-derived protein material is selected from chicken, duck, fish, and beef;

[0098] The plant-derived protein materials are selected from pea protein, soy protein isolate, and rice protein powder;

[0099] The starchy raw material is selected from potatoes, cassava, sweet potatoes, purple sweet potatoes, oats, rice, corn, and wheat, and the starchy raw material is pregelatinized before use, with a pregelatinization degree of 50%.

[0100] The functional additives include prebiotics, vitamins, and mineral ingredients.

[0101] Example 3

[0102] A method for improving the center maturity of low-temperature baked dog food includes the following steps:

[0103] S1. Mix the dog food base to obtain a mixture; the dog food base includes animal-derived protein materials, plant-derived protein materials, and starchy raw materials;

[0104] S2. Add a compound enzyme preparation to the mixture and perform enzymatic hydrolysis to obtain the enzymatic hydrolysis product; the compound enzyme preparation contains amylase, protease, phytase and non-starch polysaccharide enzyme; the mass ratio of amylase, protease, phytase and non-starch polysaccharide enzyme is 4:4:0.4:1.5.

[0105] S3. The enzymatic hydrolysis product is subjected to enzyme inactivation, flash evaporation concentration, and extrusion molding to obtain dog food pellet raw material;

[0106] S4. The raw dog food pellets are baked at a temperature below 80°C to obtain low-temperature baked dog food with a centrally matured texture.

[0107] Preferably, the amylase is α-amylase or maltose amylase;

[0108] The protease is papain or flavor protease;

[0109] The non-starch polysaccharide enzyme is β-glucanase;

[0110] The phytase is a food-grade phytase.

[0111] Preferably, the weight proportions of each component in the compound enzyme preparation are: 4 parts amylase, 4 parts protease, 0.4 parts phytase, and 1.5 parts non-starch polysaccharide enzyme.

[0112] Preferably, the enzymatic hydrolysis treatment method conditions are: temperature 50℃, pH value 6.5, enzymatic hydrolysis time 45 minutes, and water-to-material ratio of 40:1 during enzymatic hydrolysis.

[0113] Preferably, the baking temperature is 80°C and the baking time is 4 hours.

[0114] Preferably, before enzymatic hydrolysis, the mixture is further subjected to crushing and sieving to control the particle size of the material to 60 mesh.

[0115] Furthermore, the amount of each combination added during the preparation process, by weight, is as follows:

[0116] Animal-derived protein materials: 45 portions;

[0117] Plant-derived protein materials: 18 portions;

[0118] Starchy raw materials: 35 parts;

[0119] Compound enzyme preparation: 0.8 parts;

[0120] Oil: 10 parts;

[0121] Functional additives: 0.6 parts.

[0122] Control Group 1: High-temperature puffing method was used without adding enzymes. The puffing process was carried out at 130°C. Specifically, the animal-derived protein material, plant-derived protein material, and starch raw material in the proportions described in Example 3 were mixed to obtain a mixture. The moisture content of the mixture was adjusted to 28%, and the mixture was puffed at 130°C and 4MPa for 1 minute. The final moisture content was ≤10%. Cooked oil was then sprayed on the surface to obtain high-temperature puffed dog food.

[0123] Control group 2: The low-temperature baking method of the present invention was used, which differed from Example 3 in that no enzyme preparation was added and the baking was carried out at 80°C for 4 hours.

[0124] Control group 3: The low-temperature baking method was used, which differed from Example 3 in that only amylase and protease (4:4) were added, and the mixture was baked at 80°C for 4 hours.

[0125] Control group 4: The low-temperature baking method of the present invention was used, which differed from Example 3 in that the mass ratio of amylase, protease, phytase and non-starch polysaccharide enzyme was 2:2:0.8:3, and the mixture was baked at 80°C for 4 hours.

[0126] Control group 5: The low-temperature baking method of the present invention is used, which differs from Example 3 in that the mass ratio of amylase, protease, phytase and non-starch polysaccharide enzyme is 6:7:0.4:1, and the mixture is baked at 80°C for 4 hours.

[0127] Control group 6: The low-temperature baking method of the present invention is different from that of Example 3 in that the mass ratio of amylase, protease, phytase and non-starch polysaccharide enzyme is 4:7:0.8:1, and the baking is carried out at 80°C for 4 hours.

[0128] Control group 7: The low-temperature baking method of the present invention is different from that of Example 3 in that the mass ratio of amylase, protease, phytase and non-starch polysaccharide enzyme is 4:8:0.4:3, and the baking is carried out at 80°C for 4 hours.

[0129] Control group 8: The low-temperature baking method of the present invention was used, which differed from Example 3 in that: no phytase was added, and the mass ratio of amylase, protease and non-starch polysaccharide enzyme remained unchanged (4:4:1.5), and the mixture was baked at 80°C for 4 hours.

[0130] Control group 9: The low-temperature baking method of the present invention is different from that of Example 3 in that: no non-starch polysaccharide enzyme is added, the mass ratio of amylase, protease and phytase remains unchanged (4:4:0.4), and it is baked at 80°C for 4 hours.

[0131] Control group 10: The low-temperature baking method of the present invention was used, which differed from Example 3 in that: no amylase was added, and the mass ratio of protease, phytase and non-starch polysaccharide enzyme remained unchanged (4:4:1.5), and the mixture was baked at 80°C for 4 hours.

[0132] Control group 11: The low-temperature baking method of the present invention was used, which differed from Example 3 in that: no protease was added, and the mass ratio of amylase, phytase and non-starch polysaccharide enzyme remained unchanged (4:0.4:1.5), and the mixture was baked at 80°C for 4 hours.

[0133] Experimental group: Using the method of this invention, amylase, protease, phytase and non-starch polysaccharide enzymes were added and baked at 80°C for 4 hours.

[0134] Note: Gelatinization degree is the percentage of gelatinized starch out of the total starch. When raw starch is heated in a moist state, the starch granules absorb water, swell, and rupture, and the molecular chains extend to form a viscous paste. This process is called gelatinization.

[0135] Experiment 1

[0136] Twenty finished grains were randomly selected from each group, carefully cut open with a scalpel, and approximately 50 mg of starch from the geometric center of each grain was taken to determine the degree of starch gelatinization. Simultaneously, a 1 mm sample from the surface of each grain was taken to determine the surface gelatinization. During the baking process, a thermocouple was inserted into the center of each grain to monitor temperature changes in real time, and the time required for the center temperature to reach 80℃ was recorded. Each sample was measured three times, and the average value was taken. The results are shown in Table 1.

[0137] Table 1. Results of core cooking degree and heating time of dog food in each group

[0138]

[0139] As shown in Table 1, the center gelatinization degree of control group 2 was only 71.2%, exhibiting a clear phenomenon of being cooked on the outside but raw on the inside. The center gelatinization degree of control group 3 increased to 82.5%. Control groups 4-7 showed improved center gelatinization degree due to the addition of the four enzymes provided by this invention, but the effect was still lower than that of the experimental group due to improper ratio of the four enzymes: the center gelatinization degree of control group 4 was 85.8%, with a heating time of 101 minutes; the center gelatinization degrees of control groups 5, 6, and 7 were 86.5%, 87.2%, and 86.9%, respectively, with heating times of 98 minutes, 96 minutes, and 97 minutes, respectively. This demonstrates that when the enzyme ratio is improper, the synergistic effect of the four enzymes will be affected to some extent.

[0140] In controls 8-11, the central ripening degree significantly decreased when any one of the four enzymes was missing. Control group 8 lacked phytase, with a central gelatinization degree of 84.6% and a heating time of 106 minutes; control group 9 lacked non-starch polysaccharide enzymes, with a central gelatinization degree of 85.2% and a heating time of 104 minutes; control group 10 lacked amylase, with a central gelatinization degree of 80.5% and a heating time of 118 minutes; and control group 11 lacked protease, with a central gelatinization degree of 81.2% and a heating time of 116 minutes. The most significant decrease in central gelatinization degree occurred with the absence of either amylase (control group 10) or protease (control group 11). This is because amylase directly lowers the starch gelatinization activation energy, while protease disrupts the protein network, opening up heat transfer channels. However, the absence of either phytase (control group 8) or non-starch polysaccharide enzymes (control group 9) still hindered heat transfer due to the phytic acid complex and fibrous network, similarly leading to a decrease in central ripening degree.

[0141] The experimental group, using the method of this invention, achieved a center gelatinization degree of 93.8% and a surface gelatinization degree of 87.5%, with a center temperature reaching 80℃ in only 92 minutes. Compared to control groups 2-11, the experimental group exhibited the highest center gelatinization degree and the shortest heating time. Furthermore, its center gelatinization degree was significantly higher than that of control group 1, which underwent high-temperature puffing. Simultaneously, its surface gelatinization degree was lower than that of control group 1, indicating that the low-temperature baking method better preserves surface nutrients and avoids over-cooking. Control group 1, due to its instantaneous high-temperature and high-pressure treatment, reached the gelatinization temperature at the particle center instantaneously; therefore, the heating time was not recorded.

[0142] The above results indicate that the present invention produces a significant synergistic effect through the combination of amylase, protease, phytase, and non-starch polysaccharide enzymes: protease disrupts the dense structure of proteins, phytase reduces the hindrance of phytic acid complexes to heat transfer, and non-starch polysaccharide enzymes cleave the viscous fiber network. Together, the three open up heat conduction channels, while amylase cleaves some of the long starch chains, reducing the activation energy required for starch gelatinization, thus solving the technical problem of undercooked centers in low-temperature baking.

[0143] Experiment 2

[0144] The hardness of the compression test was performed using a texture analyzer (TA-XT2 type). The probe compression distance was set to 5mm. Twenty dog ​​food samples were randomly selected from each group for testing, and the maximum crushing force was recorded as the hardness value.

[0145] The surface grease condition was evaluated using the paper halo test: 20g of sample was taken from each group and placed on white A4 paper for 20 minutes. The number and diameter of the halos that appeared on the paper were observed and recorded.

[0146] The results are shown in Table 2.

[0147] Table 2 Results of Physical Quality Testing of Dog Food in Each Group

[0148]

[0149] As shown in Table 2, in terms of hardness: Control group 1 had the highest hardness, reaching 344 N, with a dense particle structure and poor brittleness. The hardness of all groups baked at low temperature was significantly lower than that of control group 1, with control group 2 having a hardness of 179 N; control group 3 having a hardness of 171 N; control groups 4-7 having a hardness that further decreased to 160-166 N; control groups 8-11 having a hardness between 167-175 N; and the experimental group having the lowest hardness, at only 151 N.

[0150] Specifically, the hardness of control groups 10 (lacking amylase) and 11 (lacking protease) was 175N and 173N respectively, which was relatively high among the low-temperature baking groups. This indicates that when amylase or protease is lacking, starch gelatinization is insufficient, the protein network is not effectively destroyed, and the particle structure remains relatively dense. The hardness of control groups 8 (lacking phytase) and 9 (lacking non-starch polysaccharide enzymes) was 168N and 167N respectively, slightly higher than control groups 4-7. This indicates that when phytase or non-starch polysaccharide enzymes are lacking, heat transfer is hindered, leading to insufficient ripening and increased hardness. The experimental group had the lowest hardness at 151N, indicating that the adopted technical solution had the strongest synergistic effect of the four enzymes, and the starch, protein, and fiber network were fully degraded, forming a uniform and loose porous structure, thus achieving the best crispness.

[0151] Regarding surface oiliness: Control group 1 showed a large number of oil halos, because high-temperature extruded dog food usually requires a large amount of oil to be sprayed on the surface to improve palatability, resulting in a greasy surface and obvious oil halos. In contrast, the low-temperature baking method showed a generally clean surface, with significantly fewer and smaller oil halos compared to the high-temperature extruded group.

[0152] In the low-temperature baking groups, the control group (groups 2-11) showed relatively more pronounced oil halos. The experimental group exhibited the best oil condition, with only a very small number of oil halos and the smallest diameter being 1-3 mm. This may be because the enzymatic treatment disrupted the dense structure of proteins and fibers in the material, creating a more uniform porous structure. This allowed the oil to be better absorbed and evenly distributed during mixing, reducing oil migration and seepage to the surface during baking, resulting in a cleaner surface quality. The absence of amylase or protease led to more significant oil seepage, indicating that these two enzymes play a crucial role in disrupting the dense structure of the material and promoting oil absorption.

[0153] The above results demonstrate that the dog food prepared by the method of this invention has the advantages of moderate hardness, good crispness, and a clean, non-greasy surface, and its physical quality is significantly better than that of the high-temperature extrusion method. The synergistic effect of the four enzymes not only improves the core ripening degree but also enhances the physical quality of the product.

Claims

1. A method for improving the center ripeness of low-temperature baked dog food, characterized in that, Includes the following steps: S1. Mix the dog food base to obtain a mixture; the dog food base includes animal-derived protein materials, plant-derived protein materials, and starchy raw materials; S2. Add a compound enzyme preparation to the mixture and perform enzymatic hydrolysis to obtain the enzymatic hydrolysis product; the compound enzyme preparation contains amylase, protease, phytase and non-starch polysaccharide enzyme; the mass ratio of amylase, protease, phytase and non-starch polysaccharide enzyme is 3-5:3-5:0.3-0.6:1-2; S3. The enzymatic hydrolysis product is subjected to enzyme inactivation, flash evaporation concentration, and extrusion molding to obtain dog food pellet raw material; S4. The raw dog food pellets are baked with oil and functional additives at a temperature below 80°C to obtain low-temperature baked dog food with central maturation.

2. The method according to claim 1, characterized in that, The amylase is selected from at least one of α-amylase and maltose amylase; The protease is selected from at least one of papain and flavor protease; The non-starch polysaccharide enzyme is selected from at least one of xylanase, cellulase, and β-glucanase; The phytase is a food-grade phytase.

3. The method according to claim 2, characterized in that, The weight proportions of each component in the compound enzyme preparation are as follows: 3-5 parts amylase, 3-5 parts protease, 0.3-0.6 parts phytase, and 1-2 parts non-starch polysaccharide enzyme.

4. The method according to claim 1, characterized in that, The conditions for the enzymatic hydrolysis treatment are: temperature 40-55℃, pH value 6.0-7.0, hydrolysis time 40-50 minutes, and water-to-material ratio of 30-50:

1.

5. The method according to claim 1, characterized in that, The baking process is carried out at a temperature of 60-80℃ for 3-5 hours, and the degree of gelatinization of the dog food after baking is ≥90%.

6. The method according to claim 1, characterized in that, Before enzymatic hydrolysis, the mixture is further subjected to crushing and sieving to control the particle size of the material to 60-80 mesh.

7. The method according to claim 1, characterized in that, The amount of each combination added during the preparation process, by weight, is as follows: Animal-derived protein materials: 40-50 portions; Plant-derived protein materials: 15-20 parts; Starchy ingredients: 30-40 parts; Compound enzyme preparation: 0.5-1.2 parts; Oils: 7-12 parts; Functional additives: 0.5-0.8 parts.

8. The method according to claim 7, characterized in that, The animal-derived protein material is selected from at least one of chicken, duck, fish, and beef; The plant-derived protein material is selected from at least one of pea protein, soy protein isolate, and rice protein powder; The starchy raw material is selected from at least one of potato, cassava, sweet potato, purple sweet potato, oat, rice, corn, and wheat, and the starchy raw material is pregelatinized before use, with a pregelatinization degree of 30%-50%. The functional additives include at least one of prebiotics, vitamins, and mineral ingredients.

9. The method for preparing low-temperature baked dog food according to any one of claims 1-8, characterized in that, By weight, it includes the following components: Animal-derived protein materials: 40-50 portions; Plant-derived protein materials: 15-20 parts; Starchy ingredients: 30-40 parts; Compound enzyme preparation: 0.5-1.2 parts; Oils: 7-12 parts; Functional additives: 0.5-0.8 parts.

10. The low-temperature baked dog food according to claim 9, characterized in that, By weight, it includes the following components: Animal-derived protein materials: 45 portions; Plant-derived protein materials: 18 portions; Starchy raw materials: 35 parts; Compound enzyme preparation: 0.8 parts; Oil: 10 parts; Functional additives: 0.6 parts.

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