Selenium-rich DHA-rich feed additive as well as preparation method and application thereof

Abstract

The invention provides a selenium-rich DHA-rich feed additive as well as a preparation method and application thereof, and belongs to the technical field of feed additives. The preparation method comprises the following steps: preparing a core material: dissolving sodium alginate in water, adding schizochytrium limacinum powder and water-soluble selenoprotein, heating and mixing to obtain a mixed solution 1; adding the mixed solution 1 into the rapeseed oil, adding polysorbate, and mixing to obtain a mixed solution 2; adding a calcium chloride solution into the mixed solution 2, centrifuging, collecting precipitate, and drying to obtain a core material; preparing a wall material: thermally melting corn viscose, then adding maltodextrin and polycaprolactone, and mixing to obtain the wall material; and coating: mixing the core material and the wall material for coating. The method is simple and easy to operate, the rancidity rate of DHA in the core material can be inhibited, the stability of DHA microalgae powder in stomachs and intestines of livestock and poultry is improved, and the conversion rate is increased. And meanwhile, the water-soluble selenoprotein in the core material and the microalgae powder rich in DHA have a synergistic effect, so that the contents of selenium and DHA in livestock and poultry products can be effectively increased.

Description

Technical Field

[0001] The present invention belongs to the technical field of feed additives, and in particular relates to a selenium-rich DHA-rich feed additive and a preparation method and application thereof. Background Art

[0002] DHA plays an important role in human growth and development. It can prevent cardiovascular disease by lowering serum triglycerides, reducing thrombosis, lowering blood pressure, and reducing related inflammatory responses. Studies have shown that DHA deficiency in the brain is closely linked to Alzheimer's disease. DHA is an essential nutrient obtained from food. As we age, the body's ability to synthesize DHA from ALA decreases, making the need for DHA more urgent for the elderly. Currently, the main ways to obtain DHA are through consuming deep-sea fish oil, algae oil, etc.

[0003] Selenium is also an essential trace element for the human body. The level of selenium directly affects human health. Studies in recent years have shown that selenium deficiency in the human body is closely related to the occurrence of various diseases such as cancer, cardiovascular disease, diabetes, and liver disease.

[0004] The coordinated effect of selenium and DHA on the regulation of human health is attracting much attention. Therefore, providing high-quality functional (selenium-rich and DHA-rich) poultry and egg products has broad market prospects. Summary of the Invention

[0005] In view of this, the purpose of the present invention is to provide a method for preparing a selenium-rich and DHA-rich feed additive, so that selenium and DHA can be added to the daily diet of livestock and poultry in the form of a feed additive, thereby increasing the selenium and DHA content in livestock and poultry products.

[0006] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions: A method for preparing a selenium-rich and DHA-rich feed additive comprises the following steps: Preparation of the core material: dissolving sodium alginate in water, adding Schizochytrium algae powder and water-soluble selenoprotein, heating and mixing to obtain a mixture 1; adding the mixture 1 to rapeseed oil, and then adding polysorbate to obtain a mixture 2; adding calcium chloride solution to the mixture 2, collecting the precipitate after centrifugation, and drying to obtain the core material; Preparing the wall material: melting corn fiber gum by heating, then adding maltodextrin and polycaprolactone, and mixing to obtain the wall material; Coating: The core material and the wall material are mixed and coated to prepare a selenium-rich and DHA-rich feed additive.

[0007] Preferably, the mass volume ratio of the sodium alginate and water is (1-2) g:100 mL; the mass ratio of sodium alginate, Schizochytrium algae powder, and water-soluble selenoprotein is 5:(1.5-3):(0.5-2).

[0008] Preferably, the heating mixing is mixing at 35-42°C.

[0009] Preferably, the mass ratio of the mixed solution 1 to rapeseed oil and polysorbate is 1:(2-4):(0.1-0.5).

[0010] Preferably, the mass ratio of the mixed solution 2 to the calcium chloride solution is (0.5-1):3, and the concentration of the calcium chloride solution is 0.3-1 mol / L.

[0011] Preferably, the mass ratio of corn fiber gum, maltodextrin and polycaprolactone is (0.5-2):0.5:(0.05-0.2).

[0012] Preferably, the mass ratio of the core material to the wall material is 1:(0.5~2).

[0013] Preferably, the water-soluble selenoprotein is any one or more of Cardamine violaceum selenopolypeptide, selenomethionine (SeMet), selenocysteine (SeCys) and selenopolysaccharide.

[0014] Another object of the present invention is to provide a selenium-rich and DHA-rich feed additive prepared by the preparation method.

[0015] Another object of the present invention is to provide the use of the preparation method or the feed additive in the preparation of high-quality functional poultry and egg products, wherein the poultry and egg products are rich in selenium and DHA.

[0016] Compared with the prior art, the present invention has the following beneficial effects: The present invention provides a method for preparing a selenium- and DHA-rich feed additive. Water-soluble selenoprotein and DHA-rich microalgae powder are prepared as a core material. The water-soluble selenoprotein has antioxidant properties. A wall material is then coated on the surface of the core material, effectively inhibiting the rancidity rate of DHA in the core material, improving the stability of the DHA microalgae powder in the gastrointestinal tract of livestock and poultry, and increasing the conversion rate of the DHA microalgae powder in eggs by 10% to 25%. Furthermore, the water-soluble selenoprotein and DHA-rich microalgae powder in the core material are added to the diet of livestock and poultry in the form of a feed additive, and can be synergistically converted into animal products, effectively increasing the selenium and DHA content in the livestock and poultry products. DETAILED DESCRIPTION

[0017] The invention provides a preparation method of a selenium-rich and DHA-rich feed additive, comprising the following steps: preparing a core material: dissolving sodium alginate in water, adding Schizochytrium algae powder and water-soluble selenoprotein, and heating and mixing to obtain a mixed solution 1; adding the mixed solution 1 to rapeseed oil, and then adding polysorbate to mix, to obtain a mixed solution 2; adding a calcium chloride solution to the mixed solution 2, collecting the precipitate after centrifugation, and drying to obtain a core material; preparing a wall material: thermally melting corn fiber gum, and then adding maltodextrin and polycaprolactone, and mixing to obtain a wall material; and coating: mixing the core material and the wall material and coating them to obtain the selenium-rich and DHA-rich feed additive.

[0018] In the present invention, the mass-to-volume ratio of sodium alginate to water is (1-2) g:100 mL, preferably (1.5-2) g:100 mL, and more preferably 2 g:100 mL; the mass ratio of sodium alginate, Schizochytrium algae powder, and water-soluble selenoprotein is 5:(1.5-3):(0.5-2), preferably 5:(1.8-2.5):(1-1.5), and more preferably 5:2:1; and the heating and mixing is performed at 35-42°C. The water used in the preparation method provided by the present invention is conventional water in the art. As an practicable embodiment, the water used in the specific embodiments of the present invention is all deionized water.

[0019] In the present invention, the mass ratio of the mixed solution 1 to the rapeseed oil and polysorbate is 1:(2-4):(0.1-0.5), preferably 1:(3-4):(0.2-0.4), and more preferably 1:4:0.4.

[0020] In the present invention, the mass ratio of the mixed solution 2 to the calcium chloride solution is (0.5~1):3, preferably 1:3, and the concentration of the calcium chloride solution is 0.3~1 mol / L, preferably 0.5 mol / L. In the present invention, the calcium chloride solution is added to the mixed solution 2 and mixed evenly, and then centrifuged. The centrifugal speed is 3000~12000rpm, preferably 10000rpm, and the centrifugal time is 5~15min, preferably 10min; after centrifugation, the precipitate is collected, and the precipitate is washed and dried to obtain the core material. The drying is carried out by conventional methods in the art. As an practicable method, spray drying is adopted in the specific embodiment of the present invention for drying.

[0021] In the present invention, the mass ratio of corn fiber gum, maltodextrin and polycaprolactone is (0.5-2):0.5:(0.05-0.2), preferably 1:0.5:(0.1-0.2), and more preferably 1:0.5:0.1.

[0022] In the present invention, the mass ratio of the core material to the wall material is 1:(0.5-2), preferably 1:1.

[0023] In the present invention, the water-soluble selenoprotein is any one or more of Cardamine violaceum selenopolypeptide, selenomethionine (SeMet), selenocysteine (SeCys) and selenium polysaccharide, and the total selenium content in the water-soluble selenoprotein is preferably 1000-2000 mg / kg.

[0024] In the present invention, rapeseed oil is used as an oil phase carrier to dissolve fat-soluble Schizochytrium algae powder (DHA) and form an oil-in-water emulsion with water-soluble selenoprotein to form the core material of the microcapsule; polysorbate is used as a non-ionic surfactant to reduce the oil-water interfacial tension, promote the homogenization of the emulsion, and form emulsion droplets with uniform particle size. Sodium alginate is used as a natural anionic polysaccharide to form the initial wall material on the surface of the emulsified emulsion droplets; then calcium ions (Ca) are added to form the emulsion droplets. 2+ ) cross-linking, ionic gelation occurs, forming a dense three-dimensional mesh gel shell that encapsulates the core material. Research conducted by the present invention has found that calcium ion concentration affects the thickness of the wall material and the release rate of selenium- and DHA-rich feed additives. The method provided by the present invention allows DHA and selenoprotein to be concentratedly released in the small intestine, where absorption efficiency is higher, and directly absorbed by intestinal epithelial cells.

[0025] During the coating process, the core material and wall material are mixed into an emulsion, atomized into tiny droplets through a spray nozzle, and rapidly dried in hot air to form microcapsules. The oil-phase core material and wall material of the present invention together form the microcapsule structure. After the water evaporates at high temperature, the wall material solidifies and sets, completely encapsulating the rapeseed oil core material. The polysorbate maintains the stability of the emulsion during the drying process, preventing the droplets from coalescing or rupturing, and ensuring the uniform morphology of the microcapsules.

[0026] This invention encapsulates Schizochytrium algae powder (rich in unsaturated fatty acids such as DHA) and water-soluble selenoproteins within microcapsules formed with a wall material, achieving the following protective and synergistic benefits: 1) Antioxidant protection: The DHA in Schizochytrium algae is highly susceptible to oxidation, while the selenium in the selenoproteins is easily inactivated in acidic or oxidative environments. The microcapsule wall material forms a physical barrier, isolating the active ingredients from oxygen and the highly oxidizing environment of gastric acid, thereby reducing oxidative degradation. 2) Targeted sustained release and efficient absorption: The microcapsules maintain a stable structure in the stomach (pH 1-3), protecting the active ingredients from gastric acid degradation. Upon entering the intestine (pH 6-8), the wall material gradually dissolves, releasing the contents. This allows the DHA and selenoproteins to be concentrated in the small intestine, where absorption is more efficient, for direct absorption by intestinal epithelial cells. 3) Taste masking and enhanced stability: The microcapsules mask the fishy odor of Schizochytrium algae and the metallic taste of the selenoproteins, while also improving the stability of both during processing and storage.

[0027] The present invention also provides a selenium-rich and DHA-rich feed additive prepared by the preparation method.

[0028] The present invention also provides the use of the preparation method or the feed additive in the preparation of high-quality functional poultry and egg products, wherein the poultry and egg products are rich in selenium and DHA.

[0029] In a specific embodiment of the present invention, Cardamine violata selenium polypeptide was purchased from Enshi Qingjiang Bioengineering Co., Ltd.; Schizochytrium truncatum powder was purchased from Jiabiyou Biotechnology (Wuhan) Co., Ltd.

[0030] The technical solutions provided by the present invention are described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0031] Example 1 A method for preparing a selenium-rich DHA-rich feed additive comprises the following steps: Preparation of core material: 2 g of sodium alginate was dissolved in 100 mL of water (heated to 65°C for dissolution), and Schizochytrium algae powder and Cardamine violaceum selenium polypeptide were added (the mass ratio of sodium alginate, Schizochytrium algae powder and Cardamine violaceum selenium polypeptide was 5:2:1, and the total selenium content in Cardamine violaceum selenium polypeptide was 1000 mg / kg), and mixed at 42°C to obtain mixed solution 1; mixed solution 1 was added to rapeseed oil, and then polysorbate was added (the mass ratio of mixed solution 1, rapeseed oil and polysorbate was 1:4:0.4) to mix to obtain mixed solution 2; calcium chloride solution was added to mixed solution 2 (the mass ratio of mixed solution 2 to calcium chloride solution was 1:3, and the concentration of calcium chloride solution was 0.5 mol / L), centrifuged (10000 rpm, 10 min), and the precipitate was collected. The precipitate was washed and dried to obtain the core material.

[0032] Preparation of wall material: heat-melt corn fiber gum, then add maltodextrin and polycaprolactone, the mass ratio of corn fiber gum, maltodextrin and polycaprolactone is 1:0.5:0.1, and mix to obtain wall material.

[0033] Coating: The core material and the wall material are mixed (the mass ratio of the core material to the wall material is 1:1), and coating is performed in a coating machine to obtain a selenium-rich and DHA-rich feed additive.

[0034] Example 2 A method for preparing a selenium-rich DHA feed additive. This embodiment differs from Example 1 in that sodium alginate, Schizochytrium algae powder, and Cardamine violae selenium polypeptide are mixed in a mass ratio of 5:2:0.5, and the mixing temperature is 35° C. The remaining steps are the same as in Example 1.

[0035] Example 3 A method for preparing a selenium-rich and DHA-rich feed additive, the difference between this embodiment and embodiment 1 is that the core material and the wall material are mixed in a mass ratio of 1:2. The remaining steps are the same as those in embodiment 1.

[0036] Example 4 A method for preparing a selenium-rich DHA-rich feed additive, the difference between this embodiment and embodiment 1 is that the core material and the wall material are mixed at a mass ratio of 1:0.5. The remaining steps are the same as those in embodiment 1.

[0037] Comparative Example 1 A method for preparing a selenium-rich and DHA-rich feed additive, wherein this comparative example differs from Example 1 in that no Schizochytrium algae powder is added to the core material. The remaining steps are the same as those in Example 1.

[0038] Comparative Example 2 A method for preparing a selenium-rich DHA-rich feed additive, the difference between this comparative example and Example 1 is that no Cardamine violaceum selenium polypeptide is added to the core material. The remaining steps are the same as Example 1.

[0039] Comparative Example 3 A method for preparing a selenium-rich DHA-rich feed additive. This comparative example differs from Example 1 in that sodium alginate, Schizochytrium algae powder, and Cardamine violae selenium polypeptide are mixed in a mass ratio of 5:1:1. The remaining steps are the same as in Example 1.

[0040] Comparative Example 4 A method for preparing a selenium-rich and DHA-rich feed additive. The difference between this comparative example and Example 1 is that no wall material is prepared and no coating is performed, and the prepared core material is used as the selenium-rich and DHA-rich feed additive.

[0041] Test Example 1 Feeding effects of feed additives prepared by different methods.

[0042] 864 healthy, well-conditioned Hy-Line grey laying hens at peak egg production (40 weeks of age) were selected and randomly divided into 12 groups, with 24 hens per group and three replicates per group. The feeding method was as follows: Treatment 1: fed only conventional feed without feed additives; Treatment 2: The feed additive prepared in Example 1 was mixed with conventional feed for laying hens and fed to laying hens at an intake of 0.36 g / hen / day, with the additive accounting for 0.3% of the conventional feed. Treatment 3: The feed additive prepared in Example 2 was mixed with conventional feed for laying hens and then fed to laying hens. The intake of the additive was 0.36 g / hen / day, and the proportion of the additive in the conventional feed was 0.3%; Treatment 4: The feed additive prepared in Example 3 was mixed with conventional feed for laying hens and then fed to laying hens. The intake of the additive was 0.36 g / hen / day, and the proportion of the additive in the conventional feed was 0.3%; Treatment 5: The feed additive prepared in Example 4 was mixed with conventional feed for laying hens and then fed to laying hens. The intake of the additive was 0.36 g / hen / day, and the proportion of the additive in the conventional feed was 0.3%; Treatment 6: The feed additive prepared in Comparative Example 1 was mixed with conventional feed for laying hens and then fed to the laying hens so that the intake of Cardamine violae selenium polypeptide was the same as that in Treatment 2; Treatment 7: The feed additive prepared in Comparative Example 2 was mixed with conventional feed for laying hens and then fed to the chickens so that the intake of Schizochytrium algae powder was the same as that in Treatment 2; Treatment 8: The feed additive prepared in Comparative Example 3 was mixed with conventional feed for laying hens and fed to laying hens at an intake of 0.36 g / hen / day, with the additive accounting for 0.3% of the conventional feed. Treatment 9: The feed additive prepared in Comparative Example 4 was mixed with conventional feed for laying hens and fed to laying hens at an intake of 0.36 g / hen / day, with the additive accounting for 0.3% of the conventional feed. Treatment 10: Cardamine violae selenium polypeptide was mixed with conventional feed for laying hens and then fed to the laying hens so that the intake of Cardamine violae selenium polypeptide was the same as that of treatment 2; Treatment 11: The Schizochytrium algae powder was mixed with the conventional feed of laying hens and then fed to the chickens so that the intake of Schizochytrium algae powder was the same as that of Treatment 2; Treatment 12: The Schizochytrium algae powder and Cardamine violae selenium polypeptide were mixed with conventional feed for laying hens and then fed to the hens so that the intake of Schizochytrium algae powder and Cardamine violae selenium polypeptide was the same as that of Treatment 2.

[0043] The first day of feeding was defined as the first day. After 20 consecutive days of feeding, the contents of α-linolenic acid, EPA, DHA, and selenium in the eggs were tested. The fatty acid content was determined according to the national standard GB5009.168-2016, and the selenium (Se) content was determined according to the national standard GB5009.93-2017. The results are shown in Table 1.

[0044] Table 1 Results of nutrient composition determination in eggs.

[0045]

[0046] Note: “ / ” means not detected.

[0047] According to the results in Table 1, the present invention can effectively increase the contents of α-linolenic acid, EPA, DHA and selenium in eggs.

[0048] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A method for preparing a selenium-rich DHA-rich feed additive, characterized in that: The steps include: Preparation of the core material: dissolving sodium alginate in water, adding Schizochytrium algae powder and water-soluble selenoprotein, heating and mixing to obtain a mixture 1; adding the mixture 1 to rapeseed oil, and then adding polysorbate to obtain a mixture 2; adding calcium chloride solution to the mixture 2, collecting the precipitate after centrifugation, and drying to obtain the core material; Prepare the wall material: heat and melt the corn fiber gum, then add maltodextrin and polycaprolactone, and mix to obtain the wall material; Coating: The core material and the wall material are mixed and coated to prepare a selenium-rich and DHA-rich feed additive.

2. The preparation method according to claim 1, characterized in that The mass volume ratio of the sodium alginate and water is (1-2) g:100 mL; the mass ratio of sodium alginate, Schizochytrium algae powder, and water-soluble selenoprotein is 5:(1.5-3):(0.5-2).

3. The preparation method according to claim 1, characterized in that The heating mixing is mixing at 35-42°C.

4. The preparation method according to claim 1, characterized in that The mass ratio of the mixed solution 1 to rapeseed oil and polysorbate is 1:(2~4):(0.1~0.5).

5. The preparation method according to claim 1, characterized in that The mass ratio of the mixed solution 2 to the calcium chloride solution is (0.5-1):3, and the concentration of the calcium chloride solution is 0.3-1 mol / L.

6. The preparation method according to claim 1, characterized in that The mass ratio of corn fiber gum, maltodextrin and polycaprolactone is (0.5~2):0.5:(0.05~0.2).

7. The preparation method according to claim 1, characterized in that The mass ratio of core material to wall material is 1:(0.5~2).

8. The preparation method according to claim 1, characterized in that The water-soluble selenoprotein is any one or more of Cardamine violaceum selenium polypeptide, selenomethionine, selenocysteine and selenium polysaccharide.

9. The selenium-rich and DHA-rich feed additive prepared by the preparation method according to any one of claims 1 to 8.

10. Use of the preparation method according to any one of claims 1 to 8 or the feed additive according to claim 9 in the preparation of high-quality functional poultry and egg products, characterized in that: The poultry and egg products are rich in selenium and DHA.

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