Vacuum freeze-dried feed for reptiles and preparation method thereof

Abstract

The present invention discloses a vacuum freeze-dried feed for reptiles and a preparation method thereof. The vacuum freeze-dried feed comprises mice, seaweed powder and a modified antimicrobial agent. The present invention prepares the modified antimicrobial agent by cross-linking the modifier and hydroxyethyl chitosan with a cross-linking agent, and then adds the modified antimicrobial agent and seaweed powder to mouse meat to prepare the reptile feed, and retains the nutrients in the feed by vacuum freeze-drying technology. Compared with the prior art, the vacuum freeze-dried feed for reptiles prepared by the present invention has certain antimicrobial properties, reduces the mold content of the feed, and has good stability of the feed, so the feed can be stored for a longer time, and the resistance of the reptiles can be effectively enhanced after taking the feed.

Description

Technical Field

[0001] The present invention relates to the technical field of freeze-dried feed, and in particular to a vacuum freeze-dried feed for reptiles and a preparation method thereof. Background Art

[0002] Reptiles, including various snakes, lizards, crocodiles, spiders, scorpions, turtles, etc., may be the choice of reptile lovers. These animals are characterized by being cold-blooded animals, living on land, and moving by crawling. Reptiles have unique physiological and behavioral characteristics, so their nutritional needs are also different. For example, snakes need high-protein, high-fat feed to support their growth and reproduction, while lizards need feed containing vitamins and minerals to maintain their health.

[0003] With the improvement of people's living standards and the change of consumption concepts, the demand for food and feed has also changed. People are more inclined to choose green, convenient and nutritious food and feed. Therefore, vacuum freeze-dried feed came into being to meet the needs of the market. Vacuum freeze-dried feed has many advantages, including maintaining the original nutrients, taste and color of the raw materials, extending the shelf life of the product, and facilitating transportation and storage. In addition, vacuum freeze-dried feed also has the characteristics of high density, high nutrition, high palatability, etc., which can meet the needs of different types of animals.

[0004] CN106497828A discloses a kind of application of Lactobacillus casei and its lyophilized preparation in pig feed, and the microorganism preservation numbering is CGMCCNo.9041 by using Lactobacillus casei, and the strain is separated from healthy pig intestinal tract and selected. The lyophilized preparation of strain is added in pig feed, can promote the intestinal health of pig, reduce the diarrhea rate of pig, improve the production performance of pig, reduce the harmful bacteria discharge in feces. But the pig feed prepared by the method selects the microorganism of Lactobacillus casei and also needs to be cultivated through culture medium, and the production link is more cumbersome, and the microorganism is easily polluted by other bacteria, and the growth environment is harsh, which is not conducive to mass production.

[0005] CN113080311A discloses a pet feed based on black soldier flies and a preparation method thereof, wherein black soldier fly worm slurry and meat paste are mixed, glutamine transaminase, plant protein auxiliary materials, animal protein auxiliary materials, and glue auxiliary materials are added, and stirred evenly; the mixed raw and auxiliary materials are compacted, refrigerated at -1-10°C for 12-36h to form a formed meat block; the formed meat block is steamed at 70-130°C, cooled to form a semi-finished meat block; the semi-finished meat block is granulated, frozen at <0°C, and then vacuum-dried to obtain pet feed. However, glutamine transaminase is required in the feed produced by this method. Transaminase is essentially a protein, which is easily denatured at high temperature, and is easily affected by temperature, and the storage time at high temperature will be shortened.

[0006] Reptiles will inevitably get sick during the breeding process. At this time, it is necessary to give the reptiles additional antibacterial drugs to enhance their resistance. However, taking these antibacterial drugs after the reptiles have diarrhea may affect the health of the reptiles. Therefore, it is necessary to enhance the resistance of the reptiles in their daily diet. Summary of the invention

[0007] In view of the above-mentioned defects of the prior art, the technical problem to be solved by the present invention is to improve the antibacterial ability of vacuum freeze-dried feed for reptiles, reduce the mold content of the feed, enhance the resistance of reptiles, and at the same time extend the shelf life of the feed.

[0008] To achieve the above object, the present invention provides a vacuum freeze-dried feed for reptiles, which comprises 50-80 parts of mice, 10-30 parts of seaweed powder, and 5-25 parts of modified antibacterial agent by weight.

[0009] Furthermore, the preparation method of the modified antibacterial agent comprises the following steps, measured in parts by weight:

[0010] S1: add 2-15 parts of the modifier to 5-20 parts of dimethyl sulfoxide, and stir the mixture at 35-50°C for 24-30h;

[0011] S2: Add 2-17 parts of the activator to the S1 mixture at room temperature and stir for 20-50 minutes;

[0012] S3: Dissolve 2-15 parts of polysaccharide in acetic acid solution, add to the S2 mixture, stir at 20-30°C for 20-30h, then dialyze the mixture to remove the solvent to obtain the modified antibacterial agent.

[0013] Preferably, the preparation method of the modified antibacterial agent comprises the following steps, in parts by weight:

[0014] S1: adding 1-9 parts of the cross-linking agent to 2-15 parts of the modifier in dimethyl sulfoxide, and stirring the mixture at 35-50°C for 24-30h;

[0015] S2: Add 2-17 parts of the activator to the S1 mixture at room temperature and stir for 20-50 minutes;

[0016] S3: Dissolve 2-15 parts of polysaccharide in acetic acid solution, add to the S2 mixture, stir at 20-30°C for 20-30h, then dialyze the mixture to remove the solvent to obtain the modified antibacterial agent.

[0017] Preferably, the modifier is any one of 3-O-methylquercetin-7-OBD-glucosyl-4′-OBD-glucoside, quercetin-7-glucoside, and 3-arabinoglucosylquercetin.

[0018] Preferably, the cross-linking agent is 2,3,4,5-tetrafluorophthalic anhydride.

[0019] Preferably, the polysaccharide is hydroxyethyl chitosan.

[0020] Preferably, the activator is a mixture of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide and N-hydroxysuccinimide.

[0021] More preferably, the activator is a mixture of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide and N-hydroxysuccinimide in a mass ratio of 1:1.5.

[0022] A method for producing vacuum freeze-dried feed for reptiles, comprising the following steps:

[0023] A1: Clean and sterilize healthy mice and mince them into meat paste;

[0024] A2 adds seaweed powder and modified antimicrobial agent to A1 and stirs evenly to obtain raw materials;

[0025] A3 pre-freezes the raw material A2 at -30 to -25°C for 100 to 130 minutes to obtain pre-frozen feed;

[0026] A4 evenly places the pre-frozen feed in A3 into a freeze-drying chamber, and sublimates and dries in a vacuum environment for 8-12 hours to obtain dry feed;

[0027] A5: heating the dry feed in A4 at 35-40°C for 8-13h to obtain vacuum freeze-dried feed for reptiles;

[0028] A6 cools the vacuum freeze-dried feed for reptiles in A5 to room temperature, and packages and seals the feed.

[0029] White mice: White mice, as one of the raw materials for vacuum freeze-dried feed for reptiles, provide a source of protein. In animal feed, protein is a nutrient necessary for animal growth and life activities. By using white mice as raw materials, high-quality protein can be provided to meet the nutritional needs of reptiles.

[0030] Seaweed powder: Seaweed powder is a natural marine plant extract, rich in a variety of nutrients and bioactive substances. It is rich in protein, minerals, vitamins and polysaccharides. As one of the raw materials for vacuum freeze-dried feed for reptiles, it can provide comprehensive nutrition for reptiles. Seaweed powder also has a variety of biological activities such as antioxidant, anti-inflammatory and antibacterial. These active ingredients help to improve the immunity of reptiles, enhance disease resistance and reduce the occurrence of diseases. In addition, seaweed powder also has the function of regulating intestinal function, which can promote digestion and absorption of reptiles and improve feed utilization.

[0031] Modifiers: These modifiers are natural compounds with good biological activities, such as antibacterial and anti-inflammatory. These modifiers can be cross-linked with hydroxyethyl chitosan under the action of a cross-linking agent, which can enhance the antibacterial effect of the modifier added to the feed alone. In addition, hydroxyethyl chitosan is a derivative of chitosan and also has antibacterial effects. The modifier and hydroxyethyl chitosan are cross-linked with a cross-linking agent to obtain modified antibacterial properties. When added to the feed and eaten by reptiles, it can improve the inhibitory effect of reptiles on pathogens. In addition, these modifiers are used to prepare modified antibacterial agents. Adding modified antibacterial agents to mouse meat as feed can also improve the taste and nutritional value of the feed, and increase the appetite and digestion and absorption rate of reptiles.

[0032] Dimethyl sulfoxide: Dimethyl sulfoxide also has good thermal stability and chemical stability, and can maintain good solubility at high temperatures. In the preparation process of modified antibacterial agents, components such as modifiers, activators and polysaccharides need to be dissolved in a certain solvent for stirring and reaction.

[0033] Activator: 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide is a commonly used activator that can react with the carboxyl groups contained in various carboxylic acids, amino acids, peptides and other molecules. Here, it can react with the carboxyl groups contained in the modifier to form a stable amide bond, while N-hydroxysuccinimide is a commonly used carboxylic acid activator that can react with the amino molecules contained in hydroxyethyl deacetylated chitosan to form a stable amide bond.

[0034] Hydroxyethyl chitosan: As a derivative of chitosan, hydroxyethyl chitosan also has antibacterial effects. Hydroxyethyl chitosan, modifiers and cross-linking agents can react to obtain modified antibacterial agents. The feed prepared by adding the modified antibacterial agent to mice has an antibacterial effect. At the same time, hydroxyethyl chitosan has good water absorption and can absorb and retain moisture in the feed, which is conducive to molding when preparing the feed. Due to its good water absorption and film-forming properties, it can make the feed softer and more elastic, and increase the appetite of reptiles. Hydroxyethyl chitosan also has film-forming properties and can form a protective film on the surface of the feed to prevent the feed from being polluted and oxidized by the external environment, which helps to maintain the quality and nutritional value of the feed.

[0035] Acetic acid: Acetic acid, as a solvent, can dissolve the polysaccharide better and form a homogeneous mixture.

[0036] Beneficial effects of the present invention:

[0037] 1. Compared with the prior art, a modified antibacterial agent is prepared by cross-linking a modifier and hydroxyethyl deacetylated chitosan through a cross-linking agent, and then the modified antibacterial agent is added to a raw material for mice to prepare feed. The modified antibacterial agent used in the feed has a broad-spectrum antibacterial effect, can effectively inhibit the growth and reproduction of bacteria, reduce the mold content in the feed, and extend the shelf life of the feed, while avoiding the use of harmful substances such as chemical preservatives.

[0038] 2. Compared with the existing technology, the feed also adds natural ingredients such as seaweed powder, which helps promote the digestion and absorption of reptiles. The feed contains healthy rat meat, seaweed powder, modified antibacterial agents and other ingredients, providing various nutrients required by reptiles, such as protein, fat, minerals, vitamins, etc., to meet the needs of reptiles for growth and development and daily activities. The feed is vacuum freeze-dried, which can well preserve the nutritional value of rat meat and has a good taste. DETAILED DESCRIPTION

[0039] Parameters for specific chemical substances used, sources.

[0040] Seaweed powder, CAS: 724424-92-4, Wuhan Huaxiang Kejie Biotechnology Co., Ltd.

[0041] Hydroxyethyl chitosan, CAS: 123938-86-3.

[0042] 3-O-Methylquercetin-7-OBD-glucosyl-4′-OBD-glucoside, CAS: 47858-32-2.

[0043] Quercetin-7-glucoside, CAS: 491-50-9.

[0044] 3-Arabinoglucosylquercetin, CAS: 23284-18-6.

[0045] 2,3,4,5-Tetrafluorophthalic anhydride, CAS: 52-12-0.

[0046] 1-(3-Dimethylaminopropyl)-3-ethylcarbodiimide, CAS: 1892-57-5.

[0047] Corn starch, product number: HY-DF1, Shandong Huiyang Chemical Co., Ltd.

[0048] Example 1

[0049] A method for producing vacuum freeze-dried feed for reptiles, comprising the following steps:

[0050] A1 removes the hair and internal organs of 50 kg electric hair clippers, puts the healthy mice without internal organs into a meat grinder and grinds them for 30 minutes using an 8 mm hole plate, and then grinds them again using a 4 mm hole plate to obtain white mouse meat paste;

[0051] A2 added 15 kg of seaweed powder and 6 kg of modified antimicrobial agent to the mouse meat paste of A1, and stirred at 100 rpm for 45 min to obtain feed raw materials;

[0052] A3 pre-freezes the feed raw material of A2 at -30°C for 100 minutes to obtain pre-frozen feed;

[0053] A4 evenly places the pre-frozen feed in A3 on the tray in the freeze-drying box. Each layer of the freeze-drying machine has a 304 stainless steel partition, which can be heated. During the drying process, the partition is heated step by step in batches, so as to supply heat to the pre-frozen feed by heat conduction and heat radiation. The feed is sublimated and dried for 11 hours at 0.5KPa to obtain dry feed.

[0054] A5: Heat the dry feed in A4 at 37°C for 10 hours to obtain a vacuum freeze-dried feed for reptiles;

[0055] A6 cools the vacuum freeze-dried feed for reptiles in A5 to room temperature, and packages and seals the feed.

[0056] The preparation method of the modified antibacterial agent comprises the following steps:

[0057] S1: 5 g of 2,3,4,5-tetrafluorophthalic anhydride was added to 5 g of 3-O-methylquercetin-7-OBD-glucosyl-4′-OBD-glucoside in 20 mL of dimethyl sulfoxide, and the mixture was stirred at 35 °C for 24 h;

[0058] S2: Mix 2.8 g of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide and 4.2 g of N-hydroxysuccinimide, add to the S1 mixture at 25°C, and stir for 30 min;

[0059] S3: 8 g of hydroxyethyl deacetylated chitosan was dissolved in 2 wt % acetic acid solution, added to the S2 mixture, stirred at 30° C. for 28 h, then dialyzed the mixture, and the solvent was removed by a rotary evaporator to obtain a modified antibacterial agent.

[0060] Example 2

[0061] The difference between Example 2 of the present application and Example 1 is that the 3-O-methylquercetin-7-OBD-glucosyl-4′-OBD-glucoside in S1 is replaced by quercetin-7-glucoside.

[0062] Example 3

[0063] The difference between Example 3 of the present application and Example 1 is that the 3-O-methylquercetin-7-OBD-glucosyl-4′-OBD-glucoside in S1 is replaced by 3-arabinoglucosylquercetin.

[0064] Comparative Example 1

[0065] The difference between Comparative Example 1 and Example 1 is that in A2, the seaweed powder is replaced with corn starch.

[0066] Comparative Example 2

[0067] The difference between Comparative Example 2 and Example 1 is that in S3, hydroxyethyl deacetylated chitosan is replaced by chitosan.

[0068] Comparative Example 3

[0069] The difference between this comparative example 3 and example 1 is that in S1, 3-O-methylquercetin-7-OBD-glucosyl-4′-OBD-glucoside is replaced by quercetin.

[0070] Comparative Example 4

[0071] The difference between this comparative example 4 and example 1 is that in S1, 2,3,4,5-tetrafluorophthalic anhydride is replaced by maleic anhydride.

[0072] Test Case

[0073] Anti-mildew test: Preparation of contaminated samples: 10 mL of mold liquid (Streptomyces albus, CGMCC4.7658) was taken and put into a spray pot to spray evenly on the products of Examples 1-3 and Comparative Examples 1-4 to prepare contaminated samples. Then, 25 g of each sample was weighed and diluted with 225 mL of distilled water to obtain a 1:10 dilution. Then 10 mL of the 1:10 dilution was taken and injected into a test tube with glass beads. The mixture was repeatedly blown and sucked to disperse the mold spores. 200 μl of the dilution was taken from each sample and spread on a culture dish. The sample was placed in a sterile environment at 20-30°C. The colony growth was observed and the mold growth was tested at 10 days and 60 days. The test results are shown in Table 1.

[0074] Decomposition rate test: Take equal weights of vacuum freeze-dried feed samples for reptiles prepared in Examples 1-3 and Comparative Examples 1-4, respectively, and record the weight as M1. After sealed and stored for 180 days at 35°C, away from light, and at a humidity of 65%, test the feed weight again, record it as M2, and calculate the feed decomposition rate. The calculation formula for the decomposition rate is: decomposition rate = (M1-M2) / M1×100%. The decomposition rate is recorded in Table 1.

[0075] Table 1 Anti-mildew test results

[0076]

[0077] According to Table 1, in Examples 1-3, the main raw materials are mouse meat paste, seaweed powder and modified antibacterial agent. Among them, mouse meat paste is the main source of protein, and seaweed powder may provide some necessary minerals and vitamins. The modified antibacterial agent may inhibit the microorganisms in the feed, has good mildew prevention effect, and good stability, so it can increase the shelf life of the feed. The difference between Example 1, Example 2, and Example 3 is that different modifiers are used. From the steric hindrance effect, in 3-O-methylquercetin-7-OBD-glucosyl-4′-OBD-glucoside, due to the presence of ortho-methyl groups, some groups in the molecule (such as hydroxyl groups) are hindered in space position, which can reduce the possibility of deformation of the molecule during heating. In quercetin, there is no obstruction of ortho-methyl groups, and the molecule is more likely to deform when heated. At the same time, because 3-O-methylquercetin-7-OBD-glucosyl-4′-OBD-glucoside contains flavonoid functional groups, it has excellent antioxidant and antibacterial effects on the prepared freeze-dried feed, and thus can have a good anti-mildew effect on the prepared feed.

[0078] The difference between Example 1 and Comparative Example 1 is that seaweed powder is used in Example 1, while starch is used in Comparative Example 1. From the perspective of bioactive ingredients, seaweed powder usually contains a variety of bioactive ingredients, such as polysaccharides, proteins, minerals, etc. These ingredients may have antibacterial effects and can inhibit the growth of microorganisms. In contrast, starch is a simple carbohydrate, and its antibacterial effect may be weaker, showing a poor anti-mildew effect.

[0079] Compared with Example 1 and Comparative Example 2, the difference is that what is used in Example 1 is hydroxyethyl chitosan, and what is used in Comparative Example 2 is chitosan. From the difference analysis of antibacterial components, hydroxyethyl chitosan introduces hydroxyethyl groups in the deacetylation process, and the introduction of these groups increases the hydrophilicity and flexibility of the polysaccharide molecule, making it have better solubility and dispersibility in aqueous solution. In contrast, chitosan lacks these hydroxyethyl groups, and its molecular structure is relatively rigid, and its solubility and dispersibility are poor. Therefore, hydroxyethyl chitosan can better exert its antibacterial effect when interacting with microorganisms. The hydroxyethyl groups in hydroxyethyl chitosan have higher reactivity, can interact with the negatively charged groups on the microbial cell wall, destroy the structure and function of the microbial cell wall, thereby inhibiting the growth of microorganisms. In contrast, the reactivity of chitosan is relatively low, and its ability to interact with microorganisms is weak.

[0080] Compared with Example 1 and Comparative Example 3, the difference is that 3-O-methylquercetin-7-OBD-glucosyl-4′-OBD-glucoside is used in Example 1, and quercetin is used in Comparative Example 3. From the perspective of spatial position, due to the complexity of its chemical structure, the spatial position of 3-O-methylquercetin-7-OBD-glucosyl-4′-OBD-glucoside may be more stable, making it less likely to undergo conformational changes or collapse above room temperature. At the same time, 3-O-methylquercetin-7-OBD-glucosyl-4′-OBD-glucoside contains multiple functional groups, including ether bonds, hydroxyl groups, and glycosides. The hydroxyl groups may increase the interaction between molecules by forming hydrogen bonds, thereby improving the stability of the prepared freeze-dried feed.

[0081] Compared with Example 1 and Comparative Example 4, Example 1 uses 2,3,4,5-tetrafluorophthalic anhydride, and Comparative Example 4 uses maleic anhydride. The fluorine atom in 2,3,4,5-tetrafluorophthalic anhydride has a strong electronegativity, which makes the whole molecule have a strong electron attraction ability. This electronic effect can enhance the activity of the anhydride, making it easier to react with the modifier and hydroxyethyl deacetylated chitosan for esterification, so that the cross-linked polymer obtained is more compact, thereby making the stability of the prepared freeze-dried feed better. In contrast, the reactivity of methyltetrahydrophthalic anhydride is lower, and a higher temperature or a longer reaction time may be required to fully participate in the reaction.

Claims

1. A vacuum freeze-dried feed for reptiles, characterized in that: In parts by weight, it comprises 50-80 parts of mice, 10-30 parts of seaweed powder, and 5-25 parts of modified antibacterial agent; The preparation method of the modified antibacterial agent comprises the following steps, measured in parts by weight: S1: adding 1-9 parts of the cross-linking agent to 2-15 parts of the modifier in dimethyl sulfoxide, and stirring the mixture at 35-50°C for 24-30h; S2: Add 2-17 parts of the activator to the S1 mixture at room temperature and stir for 20-50 minutes; S3: dissolving 2-15 parts of polysaccharide in acetic acid solution, adding to the S2 mixture, stirring at 20-30°C for 20-30h, and then dialyzing the mixture to remove the solvent to obtain a modified antibacterial agent; The modifier is any one of 3-O-methylquercetin-7-OBD-glucosyl-4′-OBD-glucoside, quercetin-7-glucoside, and 3-arabinoglucosylquercetin; The cross-linking agent is 2,3,4,5-tetrafluorophthalic anhydride; The polysaccharide is hydroxyethyl deacetylated chitosan; The activator is a mixture of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide and N-hydroxysuccinimide in a mass ratio of 1:1.

5.

2. A method for preparing the vacuum freeze-dried feed for reptiles as claimed in claim 1, characterized in that: The steps include: A1: Clean and sterilize healthy mice and mince them into meat paste; A2 adds seaweed powder and modified antimicrobial agent to A1 and stirs evenly to obtain raw materials; A3 pre-freezes the raw material A2 at -30 to -25°C for 100 to 130 minutes to obtain pre-frozen feed; A4 evenly places the pre-frozen feed in A3 into a freeze-drying chamber, and sublimates and dries in a vacuum environment for 8-12 hours to obtain dry feed; A5: heating the dried feed in A4 at 35-40°C for 8-13h to obtain a vacuum freeze-dried feed for reptiles; A6 cools the vacuum freeze-dried feed for reptiles in A5 to room temperature, and packages and seals the feed.

3. Application of the vacuum freeze-dried feed for reptiles as described in any one of claims 1 to 2 in reptile feed.

Images