Broiler chicken rich in DHA nutrient and production method thereof

Abstract

The invention relates to the field of food processing, and particularly discloses broiler chicken rich in DHA nutrient and a production method of the broiler chicken. A production method of broiler chicken rich in DHA nutrients comprises the following steps: feeding and slaughtering to obtain raw chicken, and adding chitosan into an acetic acid solution to obtain a chitosan solution; dissolving agarose with deionized water to obtain an agarose solution; mixing the chitosan solution and the agarose solution to prepare a mixed solution, and adding glycerol into the mixed solution to obtain an outer layer spraying solution; dissolving chitosan in an acetic acid solution to obtain a chitosan solution, and adding tween-80, DHA algal oil and nano cellulose to obtain an inner layer nutrient solution; the preparation method comprises the following steps: cleaning raw chicken, drying, spraying the outer layer spraying liquid, performing supercritical drying, then brushing the inner layer nutrient solution, spraying the outer layer spraying liquid again after drying, and then performing supercritical drying and packaging. According to the broiler chicken production method disclosed by the invention, the broiler chicken is rich in DHA, and the storage stability of the DHA is good.

Description

Technical Field

[0001] The present application relates to the technical field of food processing, and more specifically, to a broiler chicken rich in DHA nutrients and a production method thereof. Background Art

[0002] DHA (docosahexaenoic acid, commonly known as "brain gold") is a long-chain unsaturated fatty acid that is very important to the human body and is the most important member of Omega-3 unsaturated fatty acids. DHA is a major element for the growth and maintenance of nervous system cells and an important component of the brain and retina. It has the functions of strengthening the brain and improving eyesight, preventing cardiovascular diseases, anti-cancer, anti-inflammation, and inhibiting allergies. It is an important nutrient for maintaining human health. DHA cannot be synthesized in the human body and can only be absorbed and supplemented from the outside. Marine fish, fungi, and algae are its main sources. Therefore, screening and using such animal and plant raw materials as regulators to develop livestock and poultry products rich in DHA is of great significance and has broad application prospects for improving human health and governance.

[0003] Eggs and chicken have always been important traditional foods loved by the Chinese people, and are also ideal natural foods for humans. Eggs are not only rich in complete protein, but also contain a variety of vitamins, mineral vitamins, and are therefore called the "ideal nutrient bank" of the human body and are known as the "spirit of life." At the same time, eggs and chicken contain a small amount of DHA, which is one of the effective ways to provide DHA for people. However, the DHA content in traditional eggs and chicken is relatively low and cannot meet the human body's demand for DHA.

[0004] In the prior art, deep-sea fish oil or fish oil microcapsules or seaweed are added to broiler feed to feed broilers, so that DHA is enriched in eggs through chicken feed. Moreover, adding a certain amount of DHA to breeding feed can increase the DHA content in meat products. Although the above method has a certain effect, it takes a period of time to raise chickens before obtaining chicken containing DHA, which increases the cost and is difficult to be widely used in production. Summary of the invention

[0005] In order to shorten the production time of broilers containing DHA and make the production of broilers containing DHA more convenient and more widely used, the present application provides a broiler rich in DHA nutrients and a production method thereof.

[0006] In a first aspect, the present application provides a method for producing broilers rich in DHA nutrients, using the following technical solution: A method for producing broilers rich in DHA nutrients comprises the following steps: Feeding: During the feeding period of broiler chickens, the broiler chickens are fed with a feed having the following formula: 20-30 parts by weight of puffed corn, 5-15 parts by weight of docosahexaenoic acid, 5-15 parts by weight of DL-α-tocopheryl acetate, 2-5 parts by weight of DL-methionine, 2-5 parts by weight of algae oil, 8-12 parts by weight of fish oil, 8-12 parts by weight of sea cucumber powder, 30-50 parts by weight of soybean meal, and 10-15 parts by weight of shell powder; Slaughtering: slaughtering the broiler chicken, cleaning the internal organs, washing, and draining the water to obtain raw chicken; Preparing an outer layer spray liquid: adding chitosan to an acetic acid solution and stirring evenly to prepare a chitosan solution with a concentration of 1.5-2wt%; dissolving agarose in deionized water to prepare an agarose solution with a concentration of 1.5-2wt%; mixing the chitosan solution and the agarose solution in a mass ratio of 1:0.9-1 to prepare a mixed solution, adding glycerol in an amount of 15-20% of the mass of the mixed solution to the mixed solution, and ultrasonically homogenizing to prepare an outer layer spray liquid; Preparation of inner layer nutrient solution: dissolving chitosan in acetic acid solution to prepare a chitosan solution with a concentration of 1.5-2wt%, adding Tween-80, DHA algae oil and nanocellulose, stirring for 1-2h, homogenizing for 5-10min, and then ultrasonicating at a power of 75-80W for 3-5min to prepare an inner layer nutrient solution, wherein the mass ratio of chitosan, Tween-80, DHA algae oil and nanocellulose is 1:0.3-0.5:0.1-0.2:1-2; Broiler processing: Clean the raw chicken, dry it, evenly spray the outer layer spray liquid, let it stand at room temperature for 10-15 minutes, dry it supercritically, then apply the inner layer nutrient solution, spray it with the outer layer spray liquid again after drying, let it stand at room temperature for 10-15 minutes, then dry it supercritically, and package it to produce broilers rich in DHA nutrients.

[0007] By adopting the above technical solution, agarose, as a natural linear high molecular polymer, can form a gel by natural cooling, and no additional chemical cross-linking agent needs to be added, and the gel can be formed by physical cross-linking. There is a strong hydrogen bond between chitosan and agarose, and the chain segments of the two molecules are arranged separately and entangled with each other, thereby disrupting the original arrangement, changing their respective structures, and changing the crystallization properties accordingly, so that the agarose molecules have a certain modification effect on the chitosan molecules, thereby forming an intricate ion cross-linked network structure, so that an outer layer membrane that can complete self-healing by relying on the hydrogen bonding between molecules can be formed on the broiler. Due to the presence of hydrophobic groups, chitosan has a certain hydrophobicity, so the outer layer formed by the outer layer spray liquid has a high contact angle with water, which can significantly improve the hydrophobicity of the broiler surface and help reduce the impact of environmental humidity on DHA algae oil; The inner nutrient solution contains DHA algae oil, and nanocellulose is added to the chitosan solution. Nanocellulose has properties similar to whiskers and is similar to the chemical structure of chitosan. Under the nano effect of cellulose whiskers, the inner membrane formed by the inner nutrient solution has good tensile strength and is not easy to tear and break. In addition, since the nanocellulose whiskers have a highly oriented molecular structure and high crystallinity, they have high water resistance, thereby reducing the hydrophilicity of the inner layer. In addition, the rigid network reinforcement structure formed by the nanocellulose whiskers and chitosan weakens the hydrophilicity of the hydroxyl and amino groups on the chitosan molecular chain on the one hand, and limits the flexibility of the chitosan molecular chain on the other hand, thereby limiting the swelling of the chitosan molecular structure due to the infiltration of water molecules, and extending the passage path of water vapor, hindering the passage of water vapor, effectively improving the barrier performance to water vapor, and reducing the influence of moisture on the activity of DHA.

[0008] Spraying the outer layer spray liquid before and after applying the inner layer nutrient solution can protect the DHA algae oil contained in the inner layer membrane from both sides of the inner layer membrane, reduce the oxidation loss of the inner layer DHA, and increase the preservation rate of DHA.

[0009] Optionally, the mass ratio of the inner layer nutrient solution, the outer layer spraying solution sprayed each time and the raw chicken is 0.1-0.5:0.08-0.12:1.

[0010] By adopting the above technical solution, using the inner layer nutrient solution, the outer layer spray solution and raw chicken in the above mass ratio, not only can the muscles be quickly enriched with DHA, but also the storage stability of DHA can be improved.

[0011] Optionally, oxidized cellulose and beeswax are further added to the agarose solution, and the mass ratio of oxidized cellulose, beeswax and agarose is 0.4-0.6:0.01-0.03:1.5.

[0012] By adopting the above technical scheme, oxidized cellulose contains a large number of hydroxyl and carboxyl groups, which can form hydrogen bonds with agarose molecules, thereby improving the density of the outer film formed by the outer spray liquid and reducing the porosity. Beeswax is a natural wax with good hydrophobicity, thereby further improving the outer film's barrier capacity to oxygen and water vapor, and further improving the antioxidant capacity of DHA.

[0013] Optionally, the oxidized cellulose is prepared by the following method: defatting kapok fibers and adding them to deionized water, beating them after ultrasonication to obtain a dispersion, adding 2,2,6,6-tetramethylpiperidin-1-oxyl free radical, sodium bromide, and sodium hypochlorite solution, maintaining the pH value at 10.3-10.5, stirring for 1-1.5 hours, repeatedly washing, and drying.

[0014] By adopting the above technical scheme, the 2,2,6,6-tetramethylpiperidin-1-oxyl free radical (TEMPO) / sodium bromide / sodium hypochlorite system reacts with the lignocellulose fiber structure in an aqueous solution, oxidizes the primary alcohol hydroxyl groups of cellulose and finally converts them into carboxyl groups. The oxidized nanocellulose has a uniform width and a large aspect ratio, and can be stably dispersed in an aqueous solution without aggregation. The good dispersibility enables the cellulose and agarose solution to form a uniformly dispersed and stable mixed solution, and the oxidized cellulose is easier to combine with agarose molecules. Through hydrogen bonds and intermolecular entanglement, the mechanical properties of agarose forming a rigid structure through double helix aggregation can be effectively improved, and the ductility of the outer protective film formed by agarose and chitosan solution can be increased.

[0015] Optionally, the DHA algae oil is pretreated as follows: Mix anhydrous ethanol, deionized water and ammonia water, stir evenly, add tetraethyl silicate and DHA algae oil, heat to 60-80°C, stir evenly to obtain a particle solution, vacuum dry at 60-65°C for 45-48h, add to the chlorogenic acid solution, stir for 1-2h, and the mass ratio of DHA algae oil to tetraethyl silicate is 0.32-0.42:1.

[0016] By adopting the above technical scheme, DHA algae oil is very sensitive to external factors such as temperature, light, air, humidity, etc., and is easily oxidized. The oxidized products have certain harmful effects on the body, and the oxidized DHA will produce a rotten smell, affecting the quality and taste of the food; therefore, tetraethyl silicate is used under the action of ammonia water, anhydrous ethanol, etc., and after vacuum drying, nano-silica particles can be formed, thereby encapsulating the DHA algae oil therein, and the nano-silica particles have good stability under different environments, so the DHA algae oil loaded in the silica nanoparticles has an enhanced antioxidant capacity to the environment; and chlorogenic acid is formed by the condensation of caffeic acid and quinic acid, and is one of the most abundant polyphenols in the human diet, with strong anti-inflammatory, antigenic toxicity and antioxidant activity. Chlorogenic acid can increase the surface charge of nanoparticles, increase the electrostatic repulsion between particles, thereby reducing the aggregation between particles, improving the dispersion and stabilization of nanoparticles, and the antioxidant activity can delay the oxidation process of DHA algae oil embedded in the silica nanoparticles.

[0017] Optionally, in the broiler processing step, a mixed solution containing polydimethylsiloxane emulsion and methyltrimethoxysilane is sprayed on the raw chicken that has been supercritically dried after being sprayed with the outer layer spray liquid again, and then the mixture is evacuated to -(0.08~0.1)MPa, and then kept warm at 50-55°C for 1.5-2h, and the mass ratio of polydimethylsiloxane emulsion, methyltrimethoxysilane and raw chicken is 0.01-0.03:0.1-0.3:1.

[0018] By adopting the above technical scheme, after vacuuming, a silanization reaction is carried out on the outer film by chemical vapor deposition, so that a layer of hydrophobic silica is coated on the outer film. Polydimethylsiloxane can increase the adhesion of silica, and the hydrophobic silica can improve the barrier ability of the outer film to water vapor, and further enhance the temperature resistance of the outer film, thereby improving the antioxidant capacity of DHA.

[0019] Optionally, the supercritical drying pressure is 15-20 MPa and the temperature is 50-55°C.

[0020] In a second aspect, the present application provides a broiler chicken rich in DHA nutrients, using the following technical solution: A broiler chicken rich in DHA nutrients is prepared by the production method of a broiler chicken rich in DHA nutrients according to any one of claims 1 to 7.

[0021] In summary, this application has the following beneficial effects: 1. Since the method of the present application sequentially sprays an outer layer spray liquid, an inner layer nutrient solution and an outer layer spray liquid on raw chicken, an outer layer membrane, an inner layer membrane and an outer layer membrane are formed on the raw chicken. The inner layer membrane contains DHA algae oil, which can make the raw chicken rich in DHA. It is not necessary to spend a long time raising live chickens to obtain chicken containing DHA, which shortens the production time and is more conducive to reducing costs and promoting it universally. The outer layer membranes on both sides of the inner layer membrane can effectively protect the DHA in the inner layer membrane and reduce the effects of temperature, oxygen and humidity on the activity of DHA.

[0022] 2. In the present application, it is preferred to add oxidized cellulose and beeswax to the agarose solution of the outer layer spray liquid, so as to improve the density and hydrophobicity of the outer layer membrane and further enhance the protective effect of the outer layer membrane on DHA. DETAILED DESCRIPTION

[0023] The following examples further illustrate the present application in detail.

[0024] Example Embodiment 1: A method for producing broilers rich in DHA nutrients, comprising the following steps: S1. Feeding: During the feeding period of broiler chickens, the broiler chickens were fed with the following feed formula until they were ready for slaughter: 30 kg of puffed corn, 15 kg of docosahexaenoic acid, 15 kg of DL-α-tocopherol acetate, 5 kg of DL-methionine, 5 kg of algae oil, 12 kg of fish oil, 12 kg of sea cucumber powder, 50 kg of soybean meal, and 15 kg of shell powder; S2. Slaughtering: slaughtering the broiler chicken, cleaning the internal organs, washing, and draining the water to obtain raw chicken; S3, prepare the outer layer spray liquid: ① add 1.5kg of chitosan with a deacetylation degree of 95% to a 1.5% acetic acid solution by mass fraction, stir evenly, and prepare a chitosan solution with a concentration of 1.5wt%; ② Add 1.5 kg of agarose to deionized water, heat to 85°C, stir to dissolve, and prepare an agarose solution with a concentration of 1.5 wt%; ③ The chitosan solution and the agarose solution were mixed uniformly in a mass ratio of 1:1 to obtain a mixed solution, 15% of the mass of the mixed solution of glycerol was added to the mixed solution, and ultrasonically homogenized to obtain an outer layer spray solution; S4, prepare inner layer nutrient solution: 1.5kg chitosan with a deacetylation degree of 95% is dissolved in an acetic acid solution with a mass fraction of 1.5% to prepare a chitosan solution with a concentration of 2wt%, Tween-80, DHA algae oil and nanocellulose are added, stirred for 2h, homogenized for 5min, and then ultrasonicated for 3min at a power of 80W to prepare an inner layer nutrient solution, wherein the mass ratio of chitosan, Tween-80, DHA algae oil and nanocellulose is 1:0.5:0.2:2, DHA algae oil is selected from Xi'an Lingfeng Biotechnology Co., Ltd., model XH124, and nanocellulose is selected from Wuhan Lanabai, model EF234243; S5. Broiler processing: clean and dry the raw chicken, spray the outer layer spray liquid evenly on the surface and inside of the raw chicken, the mass ratio of the raw chicken to the outer layer spray liquid is 1:0.12, let it stand at room temperature for 15 minutes, supercritical drying, pressure of 15 MPa, temperature of 50°C, time for 4 hours; then evenly apply the inner layer nutrient solution on the surface and inside of the raw chicken, the mass ratio of the raw chicken to the inner layer nutrient solution is 1:0.5, dry at 40°C for 2 hours, then spray the outer layer spray liquid on the surface and inside of the raw chicken again, let it stand at room temperature for 15 minutes, supercritical drying, pressure of 15 MPa, temperature of 50°C, time for 4 hours, vacuum pack, the mass ratio of the raw chicken to the outer layer spray liquid is 1:0.12.

[0025] Embodiment 2: A method for producing broilers rich in DHA nutrients, comprising the following steps: S1. Feeding: During the feeding period of broiler chickens, the broiler chickens were fed with the following feed formula until they were ready for slaughter: 20 kg of puffed corn, 5 kg of docosahexaenoic acid, 5 kg of DL-α-tocopherol acetate, 2 kg of DL-methionine, 2 kg of algae oil, 8 kg of fish oil, 8 kg of sea cucumber powder, 30 kg of soybean meal, and 10 kg of shell powder; S2. Slaughtering: slaughtering the broiler chicken, cleaning the internal organs, washing, and draining the water to obtain raw chicken; S3, preparing the outer layer spraying liquid: ① adding 1.5 kg of chitosan with a deacetylation degree of 95% to a 1.5% acetic acid solution by mass fraction, stirring evenly, to obtain a chitosan solution with a concentration of 2 wt%; ② Add 1.5 kg of agarose to deionized water, heat to 85°C, stir to dissolve, and prepare an agarose solution with a concentration of 2 wt%; ③ The chitosan solution and the agarose solution were mixed uniformly in a mass ratio of 1:0.9 to obtain a mixed solution, 20% of the mass of the mixed solution of glycerol was added to the mixed solution, and ultrasonically homogenized to obtain an outer layer spray solution; S4, prepare inner layer nutrient solution: 1.5kg chitosan with a deacetylation degree of 95% is dissolved in an acetic acid solution with a mass fraction of 1.5% to prepare a chitosan solution with a concentration of 1.5wt%, Tween-80, DHA algae oil and nanocellulose are added, stirred for 1h, homogenized for 10min, and then ultrasonicated for 5min at a power of 75W to prepare an inner layer nutrient solution, wherein the mass ratio of chitosan, Tween-80, DHA algae oil and nanocellulose is 1:0.3:0.1:1, DHA algae oil is selected from Xi'an Lingfeng Biotechnology Co., Ltd., model XH124, and nanocellulose is selected from Wuhan Lanabai, model EF234243; S5. Broiler processing: clean and dry the raw chicken, spray the outer layer spray liquid evenly on the surface and inside of the raw chicken, the mass ratio of the raw chicken to the outer layer spray liquid is 1:0.08, let it stand at room temperature for 10 minutes, supercritical drying, pressure of 20 MPa, temperature of 55°C, time for 3 hours; then evenly apply the inner layer nutrient solution on the surface and inside of the raw chicken, the mass ratio of the raw chicken to the inner layer nutrient solution is 1:0.1, dry at 40°C for 2 hours, then spray the outer layer spray liquid on the surface and inside of the raw chicken again, let it stand at room temperature for 10 minutes, supercritical drying, pressure of 20 MPa, temperature of 55°C, time for 3 hours, vacuum pack, the mass ratio of the raw chicken to the outer layer spray liquid is 1:0.08.

[0026] Example 3: A method for producing broilers rich in DHA nutrients, which is different from Example 1 in that, in step S3, when preparing the outer layer spray liquid, oxidized cellulose and beeswax are added to the agarose solution, and the mass ratio of agarose, oxidized cellulose and beeswax is 1.5:0.6:0.03. The preparation method of oxidized cellulose is as follows: 50g of kapok fiber is added to a 2wt% sodium hydroxide solution and boiled for 0.5h to remove lignin and wax, washed with ethanol and water and then dried, and then added to 250g of deionized water, pulped after ultrasound, to obtain a dispersion, 106.5mg of 2,2,6,6-tetramethylpiperidine-1-oxyl free radical, 15.45g of sodium bromide, and 450mmol of sodium hypochlorite solution are added, the pH value is maintained at 10.3, stirred for 1h, repeatedly washed, and dried.

[0027] Example 4: A method for producing broilers rich in DHA nutrients, which is different from Example 1 in that, in step S3, when preparing the outer layer spray liquid, oxidized cellulose and beeswax are added to the agarose solution, and the mass ratio of agarose, oxidized cellulose and beeswax is 1.5:0.4:0.01. The preparation method of oxidized cellulose is as follows: 50g of kapok fiber is added to a 2wt% sodium hydroxide solution and boiled for 0.5h to remove lignin and wax, washed with ethanol and water and then dried, then added to 250g of deionized water, pulped after ultrasonication to obtain a dispersion, 106.5mg of 2,2,6,6-tetramethylpiperidin-1-oxyl free radical, 15.45g of sodium bromide, and 450mmol of sodium hypochlorite solution are added, the pH value is maintained at 10.5, stirred for 1.5h, repeatedly washed and dried.

[0028] Example 5: A method for producing broilers rich in DHA nutrients, which differs from Example 3 in that oxidized cellulose is not added.

[0029] Example 6: A method for producing broilers rich in DHA nutrients, which differs from Example 3 in that beeswax is not added.

[0030] Example 7: A method for producing broilers rich in DHA nutrients, which is different from Example 1 in that the DHA algae oil is pretreated as follows: Mix 200g of anhydrous ethanol, 50g of deionized water and 10g of ammonia water, stir evenly, then add 30g of tetraethyl silicate and DHA algae oil, heat to 60°C, stir evenly to obtain a particle solution, vacuum dry at 60°C for 48h, add the vacuum dried product to the chlorogenic acid solution, stir for 2h, the mass ratio of DHA algae oil to tetraethyl silicate is 0.42:1, the concentration of the chlorogenic acid solution is 1mg / mL, and the mass of the chlorogenic acid solution is 0.1 times that of the vacuum dried product.

[0031] Example 8: A method for producing broilers rich in DHA nutrients, which is different from Example 1 in that the DHA algae oil is pretreated as follows: Mix 200g of anhydrous ethanol, 50g of deionized water and 10g of ammonia water, stir evenly, then add 30g of tetraethyl silicate and DHA algae oil, heat to 80°C, stir evenly to obtain a particle solution, vacuum dry at 65°C for 45h, add the vacuum dried product to the chlorogenic acid solution, stir for 1h, the mass ratio of DHA algae oil to tetraethyl silicate is 0.32:1, the concentration of the chlorogenic acid solution is 1mg / mL, and the mass of the chlorogenic acid solution is 0.1 times that of the vacuum dried product.

[0032] Example 9: A method for producing broilers rich in DHA nutrients, which is different from Example 7 in that the vacuum dried product is not added to the chlorogenic acid solution.

[0033] Example 10: A method for producing broilers rich in DHA nutrients, which differs from Example 1 in that, in step S5, a mixed solution containing polydimethylsiloxane emulsion and methyltrimethoxysilane is evenly sprayed on the surface and inside of the raw chicken that has been sprayed with the outer layer of spray liquid again and supercritically dried, and then evacuated to -0.1MPa and kept warm at 50°C for 2h. The mass ratio of polydimethylsiloxane emulsion, methyltrimethoxysilane and raw chicken is 0.03:0.3:1. The polydimethylsiloxane emulsion is selected from Yantai Shunming New Materials Co., Ltd., model D30.

[0034] Example 11: A method for producing broilers rich in DHA nutrients, which differs from Example 1 in that, in step S5, a mixed solution containing polydimethylsiloxane emulsion and methyltrimethoxysilane is evenly sprayed on the surface and inside of the raw chicken that has been sprayed with the outer layer of spray liquid again and supercritically dried, and then the mixture is evacuated to -0.08MPa and kept warm at 55°C for .5h. The mass ratio of polydimethylsiloxane emulsion, methyltrimethoxysilane and raw chicken is 0.01:0.1:1. The polydimethylsiloxane emulsion is selected from Yantai Shunming New Materials Co., Ltd., model D30.

[0035] Example 12: A method for producing broilers rich in DHA nutrients, which is different from Example 1 in that, in step S3, when preparing the outer layer spray liquid, oxidized cellulose and methyltrimethoxysilane are added to the agarose solution, and the mass ratio of agarose, oxidized cellulose and methyltrimethoxysilane is 1.5:0.6:0.03. The preparation method of oxidized cellulose is as follows: 50g of kapok fiber is added to a sodium hydroxide solution with a concentration of 2wt% and boiled for 0.5h to remove lignin and wax, washed with ethanol and water and then dried, and then added to 250g of deionized water, pulped after ultrasound to obtain a dispersion, 106.5mg of 2,2,6,6-tetramethylpiperidin-1-oxyl free radical, 15.45g of sodium bromide, and 450mmol of sodium hypochlorite solution are added, the pH value is maintained at 10.3, stirred for 1h, repeatedly washed, and dried; and the DHA algae oil is pretreated as follows: 200g of anhydrous ethanol, 50g of deionized water and 10g of ammonia water were mixed, and 30g of tetraethyl silicate and DHA algae oil were added after stirring evenly. The temperature was raised to 60°C and stirred evenly to obtain a particle solution. The solution was vacuum dried at 60°C for 48h. The vacuum dried product was added to the chlorogenic acid solution and stirred for 2h. The mass ratio of DHA algae oil to tetraethyl silicate was 0.42:1. The concentration of the chlorogenic acid solution was 1mg / mL, and the mass of the chlorogenic acid solution was 0.1 times that of the vacuum dried product. In step S5, a mixed solution containing polydimethylsiloxane emulsion and methyltrimethoxysilane is evenly sprayed on the surface and inside of the raw chicken which is sprayed with the outer layer of spray liquid again and supercritically dried, and then evacuated to -0.1MPa and kept warm at 50°C for 2h. The mass ratio of polydimethylsiloxane emulsion, methyltrimethoxysilane and raw chicken is 0.03:0.3:1. The polydimethylsiloxane emulsion is selected from Yantai Shunming New Materials Co., Ltd. and the model is D30.

[0036] Comparative Example Comparative Example 1: A method for producing broilers rich in DHA nutrients, which differs from Example 1 in that the outer layer spray liquid is not sprayed first, and the inner layer nutrient solution and the outer layer spray liquid are applied to the raw chicken in sequence.

[0037] Comparative Example 2: A method for producing broilers rich in DHA nutrients, which is different from Example 1 in that the outer layer spraying liquid is not sprayed twice, and only the inner layer nutrient solution is applied.

[0038] Comparative Example 3: A method for producing broilers rich in DHA nutrients, which is different from Example 1 in that no agarose solution is added to the outer layer spray liquid, and a chitosan solution with a concentration of 1.5wt% is used as the outer layer spray liquid.

[0039] Comparative Example 4: A method for producing broilers rich in DHA nutrients, which differs from Example 1 in that nanocellulose is not added to the inner layer nutrient solution.

[0040] Performance testing Broilers rich in DHA nutrients were produced according to the methods in the examples and comparative examples, and the DHA increase rate and DHA preservation rate were detected according to the following method. The test results are recorded in Table 1.

[0041] 1. DHA increase rate: Take raw chicken without any pretreatment as the blank control group, detect the DHA content of the chicken in the blank control group as W1, and then detect the DHA content of the chicken prepared by the embodiment or comparative example method as W2, and calculate the DHA increase rate according to the following formula: DHA increase rate = (W2-W1) / W1×100%.

[0042] 2. DHA preservation rate: The DHA content of the chicken prepared in the embodiment or the comparative example is detected as W2, and then the prepared chicken is placed in a sealed bag and stored at 37°C for different periods of time. The DHA content of the chicken is detected as W3, and the DHA preservation rate is calculated according to the following formula: DHA preservation rate = (W3-W2) / W2×100%.

[0043] Test of DHA content: The broiler was subjected to lipid extraction and fatty acid methyl esterification and then gas chromatography determination. The sample processing method was based on the first method in GB5009.168-2016 "Determination of fatty acids in food in national food safety standard". The relative content of DHA was calculated by peak area normalization method based on the corresponding retention time, using Supelco 37 kinds of fatty acid methyl ester mixed standard qualitative analysis as a control. Gas chromatography conditions: injection port temperature 250℃, carrier gas is helium, split injection, split ratio is 1:100, injection volume is 1μL, flame ionization detector (FID) detector temperature is 330℃, Rtx-5 column (30m×0.25mm, 0.25μm), program temperature rise: 50℃, heating to 300℃ at 10℃ / min, hold for 5min, then heating to 300℃ at 5℃ / min, hold for 30min.

[0044] Table 1

[0045] It can be seen from the data in Table 1 that the DHA content in the broilers prepared in Example 1 and Example 2 is significantly increased compared to the blank control group, and after being placed at 37°C for 4 weeks, the preservation rate of DHA still reaches more than 90%, showing good stability.

[0046] Compared with Example 1, Example 3 and Example 4 further added oxidized cellulose and methyltrimethoxysilane to the agarose solution. Table 1 shows that the DHA content in broilers obtained in Example 3 and Example 4 is not much different from that in Example 1, but the storage stability of DHA is increased.

[0047] Compared with Example 3, Example 5 and Example 6 did not add oxidized cellulose in Example 5, and did not add beeswax in Example 6. Table 1 shows that the broilers prepared in Example 5 and Example 6 have weakened protection ability for DHA, and the DHA preservation rate is reduced.

[0048] Compared with Example 1, Examples 7 and 8 pre-processed the DHA algae oil. Table 1 shows that the broilers prepared in Examples 7 and 8 have rich DHA content, increased DHA preservation rate, and further enhanced DHA stability.

[0049] Compared with Example 7, Example 9 did not add the vacuum dried product to the chlorogenic acid solution. Table 1 shows that the DHA content in the broiler chicken obtained in this way was lower than that in Example 7, and the stability of DHA was reduced.

[0050] Compared with Example 1, the preservation rate of DHA in Example 10 and Example 11 is higher than that in Example 1, indicating that the broilers obtained in Example 10 and Example 11 can further improve the stability of DHA.

[0051] The optimal treatment method is adopted in Example 12, and the DHA stability is the best.

[0052] In Comparative Example 1, only a layer of inner nutrient solution was brushed on the raw chicken and a layer of outer spray solution was sprayed, while in Comparative Example 2, only a layer of inner nutrient solution was brushed. Compared with Example 1, the DHA increase rate in Comparative Example 1 and Comparative Example 2 did not change much, but the DHA preservation rate was significantly reduced, and the reduction was more obvious in Comparative Example 2.

[0053] Compared with Example 1, in Comparative Example 3, only chitosan solution was used as the outer layer spraying liquid. In Comparative Example 4, nanocellulose was not added to the inner layer nutrient solution. Compared with Example 1, the preservation rate of DHA in broilers prepared in Comparative Examples 3 and 4 was significantly reduced.

[0054] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make modifications to the present embodiment without any creative contribution as needed, but such modifications are protected by the patent law as long as they are within the scope of the claims of the present application.

Claims

1. A method for producing broilers rich in DHA nutrients, characterized in that: The following steps are involved: Feeding: During the feeding period of broiler chickens, the broiler chickens are fed with a feed having the following formula: 20-30 parts by weight of puffed corn, 5-15 parts by weight of docosahexaenoic acid, 5-15 parts by weight of DL-α-tocopheryl acetate, 2-5 parts by weight of DL-methionine, 2-5 parts by weight of algae oil, 8-12 parts by weight of fish oil, 8-12 parts by weight of sea cucumber powder, 30-50 parts by weight of soybean meal, and 10-15 parts by weight of shell powder; Slaughtering: slaughtering the broiler chicken, cleaning the internal organs, washing, and draining the water to obtain raw chicken; Preparing an outer layer spray liquid: adding chitosan to an acetic acid solution and stirring evenly to prepare a chitosan solution with a concentration of 1.5-2wt%; dissolving agarose in deionized water to prepare an agarose solution with a concentration of 1.5-2wt%; mixing the chitosan solution and the agarose solution in a mass ratio of 1:0.9-1 to prepare a mixed solution, adding glycerol in an amount of 15-20% of the mass of the mixed solution to the mixed solution, and ultrasonically homogenizing to prepare an outer layer spray liquid; Preparation of inner layer nutrient solution: dissolving chitosan in acetic acid solution to prepare a chitosan solution with a concentration of 1.5-2wt%, adding Tween-80, DHA algae oil and nanocellulose, stirring for 1-2h, homogenizing for 5-10min, and then ultrasonicating at a power of 75-80W for 3-5min to prepare an inner layer nutrient solution, wherein the mass ratio of chitosan, Tween-80, DHA algae oil and nanocellulose is 1:0.3-0.5:0.1-0.2:1-2; Broiler processing: Clean the raw chicken, dry it, evenly spray the outer layer spray liquid, let it stand at room temperature for 10-15 minutes, dry it supercritically, then apply the inner layer nutrient solution, spray it with the outer layer spray liquid again after drying, let it stand at room temperature for 10-15 minutes, then dry it supercritically, and package it to produce broilers rich in DHA nutrients.

2. The method for producing broilers rich in DHA nutrients according to claim 1, characterized in that: The mass ratio of the inner layer nutrient solution, the outer layer spraying solution sprayed each time and the raw chicken is 0.1-0.5:0.08-0.12:

1.

3. The method for producing broilers rich in DHA nutrients according to claim 1, characterized in that: Oxidized cellulose and beeswax are also added to the agarose solution, and the mass ratio of oxidized cellulose, beeswax and agarose is 0.4-0.6:0.01-0.03:1.

5.

4. The method for producing broilers rich in DHA nutrients according to claim 3, characterized in that: The oxidized cellulose is prepared by the following method: defatting kapok fibers and adding them into deionized water, beating them after ultrasonic treatment to obtain a dispersion, adding 2,2,6,6-tetramethylpiperidin-1-oxyl free radical, sodium bromide and sodium hypochlorite solution, maintaining the pH value at 10.3-10.5, stirring for 1-1.5 hours, repeatedly washing and drying.

5. The method for producing broilers rich in DHA nutrients according to claim 1, characterized in that: The DHA algae oil is pre-treated as follows: Mix anhydrous ethanol, deionized water and ammonia water, stir evenly, add tetraethyl silicate and DHA algae oil, heat to 60-80°C, stir evenly to obtain a particle solution, vacuum dry at 60-65°C for 45-48h, add to the chlorogenic acid solution, stir for 1-2h, and the mass ratio of DHA algae oil to tetraethyl silicate is 0.32-0.42:

1.

6. The method for producing broilers rich in DHA nutrients according to claim 1, characterized in that: In the broiler processing step, a mixed solution containing polydimethylsiloxane emulsion and methyltrimethoxysilane is sprayed on the raw chicken that has been supercritically dried after being sprayed with the outer layer spray liquid again, and then vacuumed to -(0.08-0.1)MPa, and then kept warm at 50-55°C for 1.5-2h, and the mass ratio of polydimethylsiloxane emulsion, methyltrimethoxysilane and raw chicken is 0.01-0.03:0.1-0.3:

1.

7. The method for producing broilers rich in DHA nutrients according to claim 1, characterized in that: The supercritical drying pressure is 15-20 MPa and the temperature is 50-55°C.

8. A broiler chicken rich in DHA nutrients, characterized in that: The broiler chicken rich in DHA nutrients is prepared by the production method of any one of claims 1-7.

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