Functional pet food and preparation method thereof

Abstract

The invention relates to the technical field of pet food, and particularly provides functional pet food and a preparation method thereof. The functional pet food provided by the invention is processed by taking animal meat paste as a main raw material through a screw extrusion process, the raw material also comprises crude plant protein, insect protein and corn fiber, and the mass ratio of the animal meat paste to the corn fiber to the crude plant protein to the insect protein is (30-40): (5-8): (10-15): (10-15). The particle size, hardness, moisture and the like of the prepared pet food are suitable for the taste and digestive system of pets, the digestion, absorption and utilization rate of the food by the pets can be effectively improved, and the amount of excrement and odor are reduced. The prepared pet food can provide various nutrients needed by pets, promote growth and development of the pets, enhance immunity, improve hair color and skin health and prevent and relieve various diseases.

Description

Technical Field

[0001] The present invention relates to the technical field of pet food, and in particular to a functional pet food and a preparation method thereof. Background Art

[0002] While pets bring joy to life, pet food has also received more attention and importance. Existing pet food often has a single effect, lacks pet nutritional functions, does not meet the various needs of pets, and has the problem of poor digestion and absorption after pets eat.

[0003] In order to obtain pet food with multiple functions, more nutrients are usually added to pet food. However, the larger amount of protein, lipids or other nutrients in pet food also limits its shelf life, resulting in a shorter shelf life of pet food. In some products, the nutrients and vitamins begin to gradually decrease during the shelf life.

[0004] At the same time, the high content of proteins, lipids or other nutrients in pet food also limits the preparation process. In the prior art, in order to protect the functional ingredients in pet food, a more complicated process is usually used to replace the operation that is harmful to the proteins, lipids or other functional ingredients. Summary of the invention

[0005] The present invention provides a functional pet food and a preparation method thereof, which are used to solve the defects of the pet food in the prior art, such as single nutritional function, short shelf life, easy loss of nutrients, etc.

[0006] When exploring the preparation process, the present invention found that high temperature, high pressure and high shearing of pet food raw materials can obtain pet food that meets the requirements of moisture and particle size. However, high temperature, high pressure and high shearing treatment will cause the fat and oil in the animal raw materials to precipitate and lose.

[0007] Further research of the present invention found that the combination of animal minced meat, plant crude protein, insect protein and corn fiber can effectively reduce oil precipitation under high temperature, high pressure and high shear treatment.

[0008] Based on this, the first aspect of the present invention provides a fermented pet food, which is made from animal minced meat as the main raw material through a screw extrusion process. The raw materials also include plant crude protein, insect protein and corn fiber, and the mass ratio of animal minced meat, corn fiber, plant crude protein and insect protein is (30-40): (5-8): (10-15): (10-15).

[0009] In the present invention, the conditions of high temperature, high pressure and high shear in the screw extrusion process are: screw extrusion speed 20-40 rpm, material feed speed 30-40 kg / h, feed water addition speed 15-25 kg / h, feed temperature 70-90°C, and outlet temperature 80-100°C.

[0010] In the formula of the pet food provided by the present invention, corn fiber itself is a by-product left over from corn processing and is mainly used in feed. Its main components are crude fiber, corn protein and a small amount of starch. It does not have the function of absorbing oil and forming itself. However, experiments have shown that under the production conditions of high temperature, high pressure and high shear, a series of degradation and reconstruction occur between corn fiber and meat protein, distiller's grains protein and insect protein, forming a more viscous gel-like substance that can absorb and fix fat well.

[0011] Furthermore, the amounts of animal minced meat, corn fiber, plant crude protein and insect protein in the present invention must meet a certain ratio in order to effectively avoid the precipitation of oil and fat.

[0012] In the fermented pet food provided by the present invention, the animal minced meat is obtained by crushing and steaming meat; the plant crude protein is one or more of beer lees and rice wine lees; and the insect protein is one or more of bamboo worms, grasshoppers and locust powder.

[0013] More specifically, the animal minced meat has a lipid content of 45%-60%, a protein content of 32%-47%, and the rest is water and ash.

[0014] Beer lees are rich in crude protein and trace elements, and have high nutritional value. The dry matter of beer lees contains 25.13% crude protein, 7.13% crude fat, 13.81% crude fiber, 3.64% ash, 0.4% calcium, and 0.57% phosphorus; in terms of amino acid composition, lysine accounts for 0.95%, methionine 0.51%, cystine 0.30%, arginine 1.52%, isoleucine 1.40%, leucine 1.67%, phenylalanine 1.31%, and tyrosine 1.15%; it also contains rich trace elements such as manganese, iron, and copper.

[0015] The raw materials used in the present invention have a wide range of protein sources and rich nutritional ingredients, so that pet food has the potential to promote the growth and development of pets, enhance immunity, improve coat color and skin health, and prevent and alleviate various diseases. However, the ingredients of insect protein and beer grains are relatively complex, which will also bring some unstable factors and may become allergens. Therefore, the present invention has conducted a lot of research on the selection of fermentation strains, and finally determined to use composite fermentation strains: Pichia kudriavzevii, Lactobacillus acid-resistant and Pediococcus pentosaceus.

[0016] In the present invention, Pichia kudriavzevii, Lactobacillus acidophilus, and Pediococcus pentosaceus are fermented at a ratio of effective viable counts of (1-2):(1-3):(1-3). Under this ratio, the composite fermentation strain can not only degrade animal and plant proteins, but also produce a large amount of functional oligopeptides. At the same time, the present invention finds that the fermentation strain and the formula can significantly reduce the content of biogenic amines in the finished pet food product.

[0017] In the fermented pet food provided by the present invention, the raw materials of the pet food include, by mass, 30-40% animal minced meat, 10-15% beer grains, 10-15% insect protein, 10-15% whey protein powder and 5-8% corn fiber, and the remainder is fermentation bacteria, nutritional enhancer and maltodextrin.

[0018] In a second aspect, the present invention provides a method for preparing the above-mentioned fermented pet food, comprising: fermenting raw materials containing animal minced meat, plant crude protein, insect protein and corn fiber, subjecting the fermentation product to high pressure and high shear at 70-100°C, and freeze-drying to obtain a finished product; before the freeze-drying process, spraying a coating agent composed of 5% trehalose and gum arabic.

[0019] The invention slices the semi-finished product quickly after high-temperature, high-pressure and high-shear processing, and sprays the flaky semi-finished product with a coating agent through a membrane technology, thereby improving the freeze-drying efficiency and shortening the freeze-drying processing time.

[0020] In one embodiment of the present invention, high temperature, high pressure and high shear are performed in a screw extrusion device.

[0021] More specifically, the method for preparing fermented pet food provided by the present invention comprises:

[0022] (1) screening, mixing and crushing the raw materials, wherein the particles of the raw materials after crushing are smaller than 60 meshes, and obtaining a mixed material;

[0023] (2) adding Pichia kudriavzevii, Lactobacillus acidophilus and Pediococcus pentosaceus to the mixed material for fermentation at a temperature of 40° C. for 16-18 h;

[0024] (3) feeding the fermentation product obtained in step (2) into a screw extruder at a screw extrusion speed of 20-40 rpm, a material feed speed of 30-40 kg / h, a feed water addition speed of 15-25 kg / h, a feed temperature of 70-90° C., and an outlet temperature of 80-100° C. to obtain a semi-finished pet food;

[0025] (4) spraying a coating agent composed of trehalose and gum arabic on the semi-finished pet food and then freeze-drying the food, wherein the freeze-drying conditions are as follows: pre-freezing at 0°C to -35°C for 3-4 hours, lowering the center temperature of the semi-finished product to -12°C to -15°C, and then continuing to treat at -35°C to -45°C for 36-48 hours;

[0026] (5) After freeze-drying, vacuum packaging is performed to obtain the finished fermented pet food product.

[0027] In a third aspect, the present invention provides the use of the fermented pet food or the preparation method for reducing the content of biogenic amines in pet food.

[0028] The present invention uses animal meat paste, plant crude protein, insect protein and corn fiber as fermentation raw materials in a breakthrough way, and selects Pichia kudriavzevii, Lactobacillus acid-fast and Pediococcus pentosaceus, and a probiotic combination with an effective live bacteria count ratio of 1:2:2 as a composite fermentation strain. The probiotic combination at this ratio can significantly reduce the harmful products of traditional fermented animal food - biogenic amines (histamine, 2-phenylethylamine, putrescine, etc.), and further improve the safety of pet food.

[0029] In a fourth aspect, the present invention further provides the use of the fermented pet food or the preparation method to increase the content of flavor substances in pet food and improve the feeding preference of pets.

[0030] In the prior art, usually only the nutritional value of pet food is considered, and less attention is paid to the flavor of pet food. In fact, only when the pet has a good preference for the food, the nutrients in the pet food can be taken by the pet.

[0031] The pet food provided by the present invention has a low content of biogenic amines, and the volatile substances cis-3-hexenyl acetate, propyl decalactone, hexaldehyde, hexanoic acid and 2,3-octanedione are all well expressed, and can attract pets to eat.

[0032] In a fifth aspect, the present invention provides the use of the above fermented pet food or the above preparation method in improving the antioxidant capacity of pet food.

[0033] In the present invention, DDPH of pet food + Clearance rate, O 2- The scavenging rate and ABTS free radical scavenging rate were tested, and the results showed that DDPH + The clearance rate reached 47.3-55.9%, O 2- The clearance rate reached 53.6-61.6%, and the ABTS free radical clearance rate reached 61.3-72.4%.

[0034] In a sixth aspect, the present invention provides the use of the above-mentioned fermented pet food or the above-mentioned preparation method in pet anti-anxiety and pet immunity enhancement.

[0035] The present invention uses animal experiments, mouse elevated cross maze method and zebrafish immune response model to verify the effect of the provided pet food on pet mood and immunity. It is finally confirmed that the pet food provided by the present invention can effectively improve the anti-anxiety ability and immunity of pets; it can regulate the emotions of pets, relieve the fear of pets in unfamiliar environments, and reduce the anxiety of pets.

[0036] The pet food prepared by the present invention is free from the influence of air, moisture, microorganisms, etc. during storage, ensuring that the nutrients and vitamins of the food will not be reduced or deteriorated during the shelf life, thereby ensuring the effectiveness and safety of the food. The pet food prepared by the present invention can achieve a shelf life of 24 months under normal temperature conditions, and can maintain good efficacy during the shelf life.

[0037] The beneficial effects of the present invention are:

[0038] (1) The pet food prepared by the present invention contains a variety of animal and plant proteins, fats, carbohydrates, vitamins and functional oligopeptides, which can provide various nutrients required by pets, promote the growth and development of pets, enhance immunity, improve coat color and skin health, and prevent and alleviate various diseases.

[0039] (2) The pet food of the present invention is prepared by adopting a high temperature, high pressure and high shear process. More specifically, the present invention adopts an advanced screw extrusion process, which can process raw materials from various sources into uniform semi-finished products through screw extrusion, thereby obtaining high-quality pet food with high protein content, low moisture content and long shelf life.

[0040] The screw extrusion process provided by the present invention can quickly process various types of raw materials into pet food, and can also select meat, fish, soybean, corn, wheat and rice proteins, so that the particle size, hardness, moisture, etc. of the prepared pet food are suitable for the taste and digestive system of pets, which can effectively improve the digestion and absorption utilization rate of food by pets, reduce the amount and odor of excrement, and also increase the pet's liking for food.

[0041] (3) The present invention uses twin-screw extruder equipment, which is widely used in the food processing and manufacturing industry. In the present invention, the focus is on solving the problem of fat and oil in animal raw materials being precipitated and lost under high temperature and high pressure processing conditions, further resulting in material loss and increased difficulty in process processing. DETAILED DESCRIPTION

[0042] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be described clearly and completely below. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0043] In the present invention, the animal raw materials are purchased from the market, namely, pig, cattle, sheep and other internal organs and fish, which are crushed, steamed at 100° C. for 30 minutes, and cooled to 40-45° C. to obtain animal minced meat;

[0044] Insect protein raw materials: bamboo worms, grasshoppers, and locusts were purchased from Shandong Langshi Insect Industry Co., Ltd., cleaned, dried, and crushed to pass through a 60-mesh sieve;

[0045] Beer lees or rice wine lees were purchased from Baoding Runxiang Biotechnology Co., Ltd.;

[0046] Whey protein powder, purchased from Fonterra (China) Co., Ltd.;

[0047] Nutritional enhancers (complex vitamins A and D) were purchased from Shanghai Licheng Biotechnology Co., Ltd.;

[0048] Corn fiber is a byproduct of corn processing, mainly used in feed. Its main components are crude fiber, corn protein and a small amount of starch. It was purchased from Shijiazhuang Qianheng Feed Co., Ltd.

[0049] The strains of Pichia kudriavzevii, Lactobacillus acidophilus, and Pediococcus pentosaceus were from the China Industrial Microbiological Culture Collection Center, and the number of viable bacteria was ≥1×10 10 .

[0050] Example 1 Raw materials and preparation method of pet food

[0051] The present invention provides a formula and a preparation method of pet food, as follows:

[0052] In this embodiment, animal minced meat accounts for 30% of the raw material mass, beer grains account for 15% of the raw material mass, insect protein accounts for 12.5% ​​of the raw material mass, whey protein powder accounts for 15% of the raw material mass, the amount of added bacteria is 0.1% of the raw material mass, corn fiber accounts for 5% of the raw material mass, the nutritional enhancer accounts for 0.02% of the raw material mass, and the rest is maltodextrin.

[0053] The preparation method of this embodiment is as follows:

[0054] (1) screening, mixing and crushing the raw materials, wherein the particles of the raw materials after crushing are smaller than 60 meshes, and obtaining a mixed material;

[0055] (2) adding a composite fermentation agent (Pichia kudriavzevii, Lactobacillus acidophilus, and Pediococcus pentosaceus in a ratio of 1:2:2 of effective viable bacteria) to the mixed material for fermentation at a temperature of 40° C. for 16-18 h;

[0056] (3) feeding the fermentation product obtained in step (2) into a screw extruder, with a screw extrusion speed of 30 revolutions per minute, a material feed rate of 35 kg / h, a feed water addition rate of 20 kg / h (the material is transported by the driving force generated by the water pumped by the pipeline), a feed temperature of 70° C., and a maximum temperature of ≤100° C. to obtain a semi-finished pet food;

[0057] (4) The semi-finished pet food is sliced ​​into 2 cm×2 cm slices, and a coating agent (5% concentration of trehalose and 1:1 mixture of gum arabic) is sprayed on the slices to form a film layer, followed by freeze-drying.

[0058] The coating agent is prepared by dissolving 2.5 g of trehalose and 2.5 g of gum arabic in 100 mL of water, stirring continuously, heating to 80° C., and cooling to form the coating agent.

[0059] The freeze-drying conditions are 0°C to -35°C pre-freezing treatment for 3-4 hours, the center temperature of the semi-finished product of the present invention is reduced to -12°C to -15°C, and then continued to be treated at -35 to -45°C for 36-48 hours;

[0060] (5) After freeze-drying, vacuum packaging is performed to obtain the finished pet food product.

[0061] Example 2

[0062] In this embodiment, animal minced meat accounts for 38% of the raw material mass, beer grains account for 12.5% ​​of the raw material mass, insect protein accounts for 15% of the raw material mass, whey protein powder accounts for 10% of the raw material mass, the added amount of bacteria is 0.1% of the raw material mass, corn fiber accounts for 7% of the raw material mass, and the nutritional enhancer accounts for 0.02% of the raw material mass, and the rest is maltodextrin.

[0063] The preparation method of this embodiment is the same as that of embodiment 1.

[0064] Example 3

[0065] In this embodiment, animal minced meat accounts for 35% of the raw material mass, beer grains account for 10% of the raw material mass, insect protein accounts for 10% of the raw material mass, whey protein powder accounts for 12.5% ​​of the raw material mass, the amount of added bacteria is 0.1% of the raw material mass, corn fiber accounts for 5% of the raw material mass, the nutritional enhancer accounts for 0.02% of the raw material mass, and the rest is maltodextrin.

[0066] The preparation method of this embodiment is the same as that of embodiment 1.

[0067] Example 4

[0068] In this embodiment, animal minced meat accounts for 40% of the raw material mass, beer grains account for 13% of the raw material mass, insect protein accounts for 12% of the raw material mass, whey protein powder accounts for 15% of the raw material mass, the amount of added bacteria is 0.1% of the raw material mass, corn fiber accounts for 8% of the raw material mass, and the nutritional enhancer accounts for 0.02% of the raw material mass, and the rest is maltodextrin.

[0069] The preparation method of this embodiment is the same as that of embodiment 1.

[0070] Example 5

[0071] In this embodiment, animal minced meat accounts for 36% of the raw material mass, beer grains account for 11% of the raw material mass, insect protein accounts for 13.5% of the raw material mass, whey protein powder accounts for 12% of the raw material mass, the added amount of bacteria is 0.1% of the raw material mass, corn fiber accounts for 7.5% of the raw material mass, nutritional enhancers account for 0.02% of the raw material mass, and the rest is maltodextrin.

[0072] The preparation method of this embodiment is the same as that of embodiment 1.

[0073] Comparative Example 1

[0074] In this comparative example, animal minced meat accounts for 50% of the raw material mass, beer grains account for 15% of the raw material mass, insect protein accounts for 12.5% ​​of the raw material mass, whey protein powder accounts for 15% of the raw material mass, the added amount of bacteria is 0.1% of the raw material mass, corn fiber accounts for 5% of the raw material mass, nutritional enhancers account for 0.02% of the raw material mass, and the rest is maltodextrin.

[0075] The preparation method of this comparative example is the same as that of Example 1.

[0076] Comparative Example 2

[0077] In this comparative example, animal minced meat accounts for 45% of the raw material mass, beer grains account for 15% of the raw material mass, insect protein accounts for 12.5% ​​of the raw material mass, whey protein powder accounts for 15% of the raw material mass, the added amount of bacteria is 0.1% of the raw material mass, corn fiber accounts for 10% of the raw material mass, nutritional enhancers account for 0.02% of the raw material mass, and the rest is maltodextrin.

[0078] The preparation method of this comparative example is the same as that of Example 1.

[0079] Comparative Example 3: Direct freeze drying

[0080] This comparative example is the same as Example 5, except that, in this comparative example, after obtaining the semi-finished pet food, freeze-drying is directly performed, and the freeze-drying conditions are 0°C to -35°C pre-freezing treatment for 3-4 hours, and the central temperature of the semi-finished product of the present invention is reduced to -12°C to -15°C, and then continued to be treated at -35 to -45°C for 36-48 hours.

[0081] Comparative Example 4: Spray coating and air drying

[0082] This comparative example is the same as Example 5, except that, after obtaining the semi-finished pet food, the semi-finished pet food is sprayed with a coating agent (5% trehalose and gum arabic mixture) and then air-dried. The air-drying condition is drying in a forced air drying oven at 90-100°C for 24 hours.

[0083] Comparative Example 5

[0084] This comparative example is the same as Example 1, except that the composite bacteria used in this comparative example are Lactobacillus casei and Lactobacillus plantarum in a ratio of 1:1 for fermentation.

[0085] Experimental Example 1 Detection of biogenic amine content

[0086] Biogenic amines are compounds that occur naturally in food, including histamine, tyramine, phenylethylamine, etc. If the content of biogenic amines in pet food is too high, it may cause pet allergies or other health problems. Therefore, biogenic amines are controlled as an important quality monitoring indicator of pet food.

[0087] The detection method is based on GB 5009.208 "National Food Safety Standard Determination of Biogenic Amines in Food". When detecting biogenic amines by HPLC, octadecyl bonded phase silica gel is used as filler, 0.05 mol / L potassium dihydrogen phosphate solution-acetonitrile (85%:15%) is used as mobile phase, column temperature is 35°C, and detection wavelength is 260nm. Biogenic amines have low ultraviolet absorption and cannot emit fluorescence, so biogenic amines need to be derivatized before or after the column before HPLC detection. Pre-column derivatization is more commonly used than post-column derivatization.

[0088] Table 1 shows the results of the detection of biogenic amines in the finished pet food products prepared in the examples and comparative examples.

[0089] Table 1 Detection values ​​of biogenic amines in the finished pet food products prepared in the examples and comparative examples

[0090]

[0091] From the results in Table 1, it can be seen that the composite probiotic formula (1:2:2 of Pichia kudriavzevii, Lactobacillus acid-fast, and Pediococcus pentosaceus) provided in the embodiment of the present invention can effectively reduce the content of biogenic amines in the process of preparing pet food.

[0092] At the same time, the present invention finds that when Pichia kudriavzevii, Lactobacillus acidophilus, and Pediococcus pentosaceus are fermented in a ratio of 1:2:2 on the formula of the present invention, in addition to degrading animal and plant proteins, a large amount of functional oligopeptides can also be produced.

[0093] Experimental Example 2 Total number of probiotic colonies

[0094] Objective: To evaluate the effects of different formulations on the total probiotic colony count;

[0095] Method: GB 4789.35-2016 National Food Safety Standard Food Microbiology Test Lactic Acid Bacteria Test Table 2 shows the total number of probiotic colonies of the pet food prepared in the Examples and Comparative Examples at the initial stage and after being kept at 42°C for 6 months.

[0096] Table 2 Total number of probiotic colonies in pet food prepared in Examples and Comparative Examples

[0097]

[0098]

[0099] The present invention adds 0.1% of the strain, and the total number of probiotic colonies of the strain is on the order of 10 11 The initial product obtained in the embodiment contains 10 9 ; There was no significant difference in the efficacy of probiotics of the same order of magnitude in the microbial detection results.

[0100] The results in Table 2 show that the screw extrusion and freeze-drying process ensures that the total number of probiotic colonies produced during fermentation is maintained at the same level as the initial product during the shelf life.

[0101] Table 3 Functional oligopeptide content

[0102]

[0103] The results in Table 3 show that different fermentation strains affect the production of functional oligopeptides.

[0104] Experimental Example 3 Volatile flavor substances

[0105] Objective: To evaluate the effects of different schemes and processes (Examples 1-5 and Comparative Examples 1-4) on volatile flavor substances;

[0106] Detection method:

[0107] Extraction of flavor components: The sample was crushed and dissolved in ethanol (95%), 1 mL of the sample extract was taken and placed in a 10 mL sampling bottle, and a 50 / 30 μm DVB / CAR / PDMS extraction head was inserted to extract for 30 min at 90°C, the extraction head was quickly removed and immediately inserted into the injection port, and the sample was injected after thermal desorption at 280°C for 2 min. Gas chromatography conditions: The chromatographic column was a DB-5MS elastic quartz capillary column (30m×0.25mm×0.25μm), and a program temperature was used, with the initial column temperature at 40°C, maintained for 3 min, and then increased to 240°C at 5°C / min, maintained for 42 min; the injection port temperature was 280°C; the carrier gas was high-purity helium (He) (99.999%); the carrier gas flow rate was 1.0 mL / min; non-split injection was used. Conditions: electron ionization (EI) source; ion source temperature 200°C, quadrupole temperature 150°C, electron energy 70 eV; mass range 20-500 amu; detection voltage 1.2 kV; full scan mode.

[0108] Qualitative and quantitative methods: The total ion flow of volatile components was obtained by full scanning mode of the system, and each peak was compared and analyzed with the standard spectral library (Wiley, Replib, Nist, Manilib) by computer. The similarity index (SI) above 800 was taken as the qualitative result of volatile flavor components, and the relative content of volatile flavor components was calculated by peak area normalization method. The results are shown in Table 4. Several main characteristic flavor substances were taken for verification.

[0109] Table 4 Volatile substance detection of pet food prepared in Examples and Comparative Examples

[0110]

[0111]

[0112] Experimental Example 4 Antioxidant Activity Test

[0113] The samples provided in the embodiments of the present invention and the comparative examples were crushed and dissolved, and then DDPH was detected. + , O 2- The scavenging rate and ABTS free radical scavenging rate, the test results are shown in Table 5, and the specific test methods are as follows:

[0114] (1)DDPH +Method for determination of clearance rate: weigh 2g of sample and add 18g of deionized water, shake well and centrifuge at 4500 rpm for 10 minutes. Then take the supernatant and pour it into a container, add deionized water (total mass 20g) to the centrifugal precipitate and centrifuge again, the centrifugation conditions are the same as above. The supernatants of the two centrifuges are mixed, then ultrasonically extracted for 30 minutes, filtered, the filtrate is evaporated to dryness in a 65℃ water bath, dissolved with an appropriate amount of 95% ethanol, fixed to a 25mL volumetric flask, high-speed centrifuge (8000 rpm, centrifuge for 10 minutes), take the supernatant, pass through a 0.45μm microporous filter membrane, and obtain the sample to be tested.

[0115] DPPH is a stable free radical. Its ethanol solution is purple and has a strong absorption peak at 515nm. 0.8g / L of sample solution was added to the same volume of reaction system (5mL 95% ethanol 0.2mmol / LDPPH, pH=8.2), and pure water was used as the reference for zero adjustment during colorimetry. After reacting in a 25℃ water bath for 30min, the absorbance was measured at 515nm. Three parallel samples were measured, and the average value was calculated to calculate the free radical scavenging rate.

[0116] Free radical scavenging rate = [1-A1 / A0] × 100%;

[0117] In the above formula, A0 is DPPH without sample added + The absorbance at 515 nm, A1 is the absorbance at 515 nm after the sample solution reacts with DPPH.

[0118] (2)O 2- Determination of free radical generation and scavenging rate: Pyrogallol can undergo self-oxidation reaction under weak alkaline conditions to produce O 2- Free radicals, O 2- Free radical scavengers can suppress the absorption peak of pyrogallol self-oxidation products at λ = 420 mm. Using a UV-visible spectrophotometer to monitor, O 2- The generation and O 2- Free radical scavenging rate. Take 4.5mL of 50mmol / L Tris-HCl buffer solution with pH=8.2, 4.2mL of distilled water, mix well and keep warm in a 25℃ water bath for 20min. Take it out and immediately add 0.3mL of 0.2mmol / L pyrogallol preheated at 25℃, with a total volume of 9.0mL. Measure the A420 value at 10s after the reaction is started (using pH8.2 Tris-HCl buffer as a reference) to obtain the light absorption value of the blank tube (i.e. A0). The reagents to be measured are the same as above, except that 2mL is added before adding pyrogallol, and the distilled water is reduced by the corresponding volume. The A420 value at 10s after the reaction is started (using the sample solution with the same concentration but without pyrogallol as a reference) is the light absorption value of the tube to be measured (i.e. A1). 2-Free radical scavenging rate S% = (A0-A1) / A0×100%.

[0119] (3) Accurately take 2.0 mL of ABTS+ solution and add 10 μL of the pretreated sample solution to it. Add anhydrous ethanol to the blank tube as the control group, and replace ABTS+ with buffer solution in the control tube. Place it at room temperature and in a light-proof environment for a total of 8 minutes. Then measure the absorbance at a wavelength of 734 nm. Each sample is measured in parallel 3 times. The clearance formula is:

[0120]

[0121] Where Ai: absorbance of the reaction when 2.0 mL of ABTS solution is added to 10 μL of sample solution; Aj: absorbance of the reaction when 2.0 mL of buffer solution is added to 10 μL of sample solution; A0: absorbance of the reaction when 2.0 mL of ABTS solution is added to 10 μL of anhydrous ethanol.

[0122] Table 5 Antioxidant capacity of pet food products prepared in Examples and Comparative Examples

[0123]

[0124] The results in Table 5 show that the pet food prepared by the embodiment of the present invention has strong antioxidant capacity. + Clearance, DDPH + The scavenging rate and ABTS free radical scavenging rate were significantly higher than those of the pet food obtained in the comparative example.

[0125] Experimental Example 5 Animal Test - Mouse High Platform Cross Maze Method Verifies the Effect of the Present Invention on Alleviating Fear of Being Alone and Anti-anxiety of Pets

[0126] The reference anxiety model high platform plus maze method, the high platform plus maze used was manufactured by Shanghai Jiliang Software Technology Co., Ltd. The high platform plus maze is a maze similar to a "cross" shape consisting of two open arms and two closed arms, and the maze is 50 cm above the ground. 60 mice were randomly divided into 6 groups: blank control group, test group, positive control group, diazepam (a second-class psychotropic drug commonly used in clinical improvement of anxiety, 2.5 mg kg -1) 10 mice / group. Each mouse was placed individually in a square mouse cage with a volume of about 15cm×15cm×12cm. Each group of experimental animals was gavaged with samples of corresponding concentrations, and the blank control group was gavaged with the same volume of normal saline. The drug was administered continuously for 7 days. One hour after the last drug administration, the mouse was placed in the center of the maze with its head facing the open arm, and the observer was at least 1m away from the center of the maze. The room temperature in the laboratory was around 20℃, kept quiet, and illuminated with animal lights. Before the test, each rat was allowed to move freely in the animal box for 5 minutes, and then quickly transferred to the central platform of the elevated plus maze. The video tracking system automatically recorded the number of times the rat entered the open and closed arms and the time it stayed in the two arms during the experimental period (usually 5 minutes) (the standard for entering and exiting the arms should be strictly defined, based on all four limbs entering the arms or both front paws exiting the arms). The percentage of the number of times the rats entered the open arms and the time they stayed in the open arms to the total number of times (the sum of the number of times they entered the open arms and the closed arms) and the total time (the sum of the time they stayed in the open arms and the closed arms) were calculated and used as indicators to evaluate anxiety.

[0127] The data obtained from each test group in this experiment conformed to the normal distribution, and the average value of the results of each group was selected to calculate the percentage of arm opening times and the percentage of arm opening time.

[0128] The more times the animal opens its arms and the higher the percentage of time it opens its arms, the more significant the antianxiety effect of the tested substance is. The antianxiety test results are shown in Table 6.

[0129] Table 6 Anti-anxiety test results of pets after eating the pet food of the embodiment and the comparative example

[0130]

[0131]

[0132] Experimental Example 6 Animal Test 2—Verification of the Immunity-Enhancing Efficacy of the Present Invention

[0133] The animal experiment selected the zebrafish immune response model. Because male zebrafish have higher tolerance, all male zebrafish were selected in this experiment to construct a zebrafish inflammation model, and interleukins IL-1α, IL-1β, and tumor necrosis factor TNF-α were detected. The experimental detection samples were derived from zebrafish intestinal cells. Among them, interleukins IL-1α, IL-1β, and tumor necrosis factor TNF-α are several key indicators when the animal body produces inflammation.

[0134] This experiment was repeated three times for the pet food of the embodiment and the comparative example, and the data test was statistically significant. The experimental results in Table 7 confirmed that the product of the present invention can regulate inflammation and improve the body's immunity to fight against fatigue and anxiety caused by physiological changes.

[0135] Table 7 Immunity test results of pets after eating the pet food of the embodiment and the comparative example

[0136] Sample set IL-1α IL-1β TNF-α Model Group 2502 603 807 Comparative Example 1 2009 575 772 Comparative Example 2 2164 561 660 Comparative Example 3 2199 524 522 Comparative Example 4 2100 495 596 Example 1 1914 386 490 Example 2 1860 422 469 Example 3 1877 371 432 Example 4 1520 402 466 Example 5 1587 421 481

[0137] Example 7 Physical and Chemical Properties of Pet Food

[0138] In this experimental example, the particle hardness, brittleness, initial moisture content and whether oil and fat are precipitated of the pet food obtained in the embodiment and the comparative example are tested. The results are shown in Table 8.

[0139] Table 8 Physical and chemical properties of pet food in Examples and Comparative Examples

[0140]

[0141] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A fermented pet food, which is made from animal minced meat as the main raw material through a screw extrusion process, characterized in that: The raw materials also include plant crude protein, insect protein and corn fiber, and the mass ratio of animal minced meat, corn fiber, plant crude protein and insect protein is (30-40): (5-8): (10-15): (10-15).

2. The fermented pet food according to claim 1, characterized in that The animal minced meat is obtained by crushing and steaming meat; the plant crude protein is one or more of beer lees and rice wine lees; and the insect protein is one or more of bamboo worms, grasshoppers and locust powder.

3. The fermented pet food according to claim 1, characterized in that The fermentation bacteria are Pichia kudriavzevii, Lactobacillus acid-fast and Pediococcus pentosaceus.

4. The fermented pet food according to any one of claims 1 to 3, characterized in that The raw materials of the pet food include, by mass, 30-40% animal minced meat, 10-15% beer grains, 10-15% insect protein, 10-15% whey protein powder and 5-8% corn fiber, and the remainder is fermentation bacteria, nutritional enhancer and maltodextrin.

5. The method for preparing fermented pet food according to any one of claims 1 to 4, characterized in that: include: Animal meat paste, plant crude protein, insect protein and corn fiber are used as the main raw materials for fermentation, and the fermentation products are freeze-dried to obtain the finished product; Preferably, before freeze-drying, a coating agent consisting of trehalose and gum arabic is sprayed.

6. The preparation method according to claim 5, characterized in that: include: (1) screening, mixing and crushing the raw materials, wherein the particles of the raw materials after crushing are smaller than 60 meshes, and obtaining a mixed material; (2) adding effective viable counts of Pichia kudriavzevii, Lactobacillus acidophilus and Pediococcus pentosaceus in a ratio of (1-2):(1-3):(1-3) to the mixed material for fermentation at a temperature of 40° C. for 16-18 h; (3) feeding the fermentation product obtained in step (2) into a screw extruder at a screw extrusion speed of 20-40 rpm, a material feed speed of 30-40 kg / h, a feed water addition speed of 15-25 kg / h, a feed temperature of 70-90° C., and an outlet temperature of 80-100° C. to obtain a semi-finished pet food; (4) spraying a coating agent composed of trehalose and gum arabic on the semi-finished pet food and then freeze-drying the food, wherein the freeze-drying treatment conditions are: pre-freezing at 0°C to -35°C for 3-4 hours, lowering the center temperature of the semi-finished product to -12°C to -15°C, and then continuing to treat at -35°C to -45°C for 36-48 hours; (5) After freeze-drying, vacuum packaging is performed to obtain the finished fermented pet food product.

7. Use of the fermented pet food according to any one of claims 1 to 4 or the preparation method according to any one of claims 5 to 6 in reducing the content of biogenic amines in pet food.

8. Use of the fermented pet food according to any one of claims 1 to 4 or the preparation method according to any one of claims 5 to 6 in increasing the content of flavor substances in pet food and improving the feeding preference of pets.

9. Use of the fermented pet food according to any one of claims 1 to 4 or the preparation method according to any one of claims 5 to 6 in improving the antioxidant capacity of pet food.

10. Use of the fermented pet food according to any one of claims 1 to 4 or the preparation method according to any one of claims 5 to 6 in pet anti-anxiety and pet immunity enhancement.

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