Production process of a kind of moina phase microencapsulated compound feed for prawn

Abstract

The application provides a production process of a microencapsulated shrimp feed for the post-larva stage, which realizes uniform proportioning of raw materials through ingredient mixing and secondary mixing, completes fine processing of the raw materials through a segmented type of crushing, forms granules at normal temperature and pressure through wet granulation, controls the moisture content of the materials through fluidized bed drying, completes fat spraying and coating processing through fluidized bed treatment, accurately selects qualified granules through detection and screening, maintains a low-oxygen state inside the package through sealing and packaging, and improves the hygiene and safety of the feed through irradiation sterilization. Each process cooperates with each other, can stably output feed granules with a particle size D90 of less than 130 mu m, effectively adds and retains heat-sensitive nutrients, guarantees the balanced nutrition of the product, improves the water stability of the feed through coating treatment, is not easy to cause water mixing when put into water, can improve the water breeding environment, and reduces feed waste. The process can realize batch production to meet the use demand of the market, and provides technical support and reference basis for the production of the post-larva stage feed.

Description

Technical Field

[0001] This invention relates to the field of shrimp compound feed technology, and in particular to a production process for a micro-encapsulated compound feed for mysid shrimp. Background Technology

[0002] The mysid stage is a crucial stage in the development of shrimp larvae, transitioning them to a benthic lifestyle. Seedling cultivation during this period requires extremely high adaptability to the initial feed. Currently, the initial feeds widely used in shrimp seedling production are mainly divided into two categories: biological feeds and traditional artificial micro-particle feeds. Biological feeds mainly consist of artificially bred small aquatic animals such as rotifers and Artemia nauplii, while traditional artificial micro-particle feeds are mainly processed using extrusion or crushing processes and are currently the main type of feed in large-scale shrimp seedling production.

[0003] However, traditional feed processing techniques have significant shortcomings. Specifically, crushing processes struggle to precisely control feed particle size, and extrusion processes have limited particle size control capabilities. Neither can stably produce finely granulated feed suitable for the consumption of mysid shrimp. Furthermore, high-temperature processes such as extrusion easily destroy heat-sensitive nutrients in raw materials, leading to the loss of key nutrients. Uncoated particles have poor stability in water, easily dissolving and clouding the water after feeding, resulting in feed waste and water pollution. These problems prevent traditional feeds from meeting the feeding and nutritional needs of mysid shrimp larvae, thus affecting the cultivation quality and survival rate of shrimp seedlings. Summary of the Invention

[0004] To address the shortcomings mentioned above in the background technology, the present invention provides a production process for micro-encapsulated shrimp compound feed during the mysid stage, the production process comprising the following steps: Ingredient mixing: The raw materials to be crushed are batched and mixed to obtain a mixture. Segmented pulverization: The mixture is first ultra-fine pulverized to a particle size D90≤38μm, and then air-jet pulverized to a particle size D90≤23μm to obtain pulverized material; Secondary mixing: The pulverized material is mixed with one or more of the following: high-fat raw materials, heat-sensitive raw materials, liquid and paste-like raw materials, to obtain the material to be granulated; Wet granulation: The material to be granulated is subjected to wet granulation at room temperature and pressure to obtain wet granules; Fluidized bed drying: The wet particles are subjected to fluidized bed drying, with the inlet air temperature controlled at 50-75℃ and the material temperature at 40-60℃, until the material moisture content is <10%, to obtain the dried material; Fluidized bed treatment: The dried material is subjected to fat spraying and coating treatment in a fluidized bed in sequence, and the coating weight gain is 0.5-5%, to obtain micro-coated compound feed; Testing and screening: Moisture and particle size of micro-coated compound feed are tested to control material moisture ≤10% and particle size D90 <130μm; Sealed packaging: The sieved shrimp feed is filled into sealed containers, and an oxygen absorber is added to ensure that the residual oxygen content in the container is less than 0.1%, thus obtaining packaged feed; Irradiation sterilization: The packaged feed is sterilized by gamma irradiation to obtain the finished product of micro-encapsulated shrimp compound feed for mysid shrimp.

[0005] In the above-mentioned improved production process implementation, the ingredient mixing and the secondary mixing are carried out using a single-shaft paddle mixer, and the coefficient of variation of mixing uniformity is ≤5%.

[0006] In the above-mentioned improved production process embodiments, in the segmented pulverization, the parameters of the ultrafine pulverization are: fan frequency 44-49Hz, grading frequency 50-60Hz, main unit frequency 48-55Hz, feeding frequency 11-15Hz, and pulverization temperature <78℃; the parameters of the airflow pulverization are: air source pressure 0.8MPa, fan frequency 37-45Hz, grading frequency 60-95Hz, and feeding frequency 35-48Hz.

[0007] In the above-mentioned improved production process embodiments, in the wet granulation, the binder used is selected from one or more of starch, pregelatinized starch, gelatin, dextrin, alginate, and sodium hydroxymethyl cellulose, and the binder concentration is 0.2-3% and the addition amount is 0.5-5%; the stirring paddle speed is 60-170 rpm, the granulation blade speed is 800-2000 rpm, and the spraying pressure is 0.05-0.6 MPa.

[0008] In the above-mentioned improved production process implementation, in the fluidized bed drying process, the inlet air volume is 10-17 m³ / min, the fan speed is 1700-2500 rpm, and the exhaust air temperature is <60℃.

[0009] In the above-mentioned improved production process embodiments, in the fluidized bed treatment, the materials used for the fat spraying and coating treatment are selected from one or more of fish oil, phospholipid oil, gelatin, corn gluten, alginate, cellulose derivatives, stearic acid, and glyceryl monostearate.

[0010] In the above-mentioned improved production process implementation, the inlet air temperature during the coating treatment stage is 53-68℃, the inlet air volume is 12-17m³ / min, the fan speed is 2000-2800rpm, and the atomization pressure is 0.05-0.15MPa.

[0011] As can be seen from the above description of the structure of the present invention, compared with the prior art, the present invention has the following advantages: The present invention achieves uniform proportioning of raw materials through batching and secondary mixing, completes fine processing of raw materials through segmented crushing, forms granules by wet granulation at normal temperature and pressure, controls the moisture content of materials by fluidized bed drying, completes fat spraying and coating processing by fluidized bed treatment, accurately screens qualified granules by detection and sieving, maintains a low oxygen state inside the packaging by sealed packaging, and improves the hygiene and safety of feed by irradiation sterilization. The coordinated operation of each process can accurately control the particle size of feed particles and stably produce micro-encapsulated compound feed that meets the feeding needs of shrimp during the mysid stage, thereby improving the cultivation quality and survival rate of shrimp seedlings. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the process of the present invention. Detailed Implementation

[0013] To make the objectives, technical solutions, and advantages of this application clearer, the application will now be described in further detail with reference to the accompanying drawings.

[0014] This invention discloses a production process for a microencapsulated shrimp compound feed during the mysid stage, as shown in the attached figure. Figure 1 As shown, the production process consists of the following steps: ingredient mixing, segmented crushing, secondary mixing, wet granulation, fluidized bed drying, fluidized bed treatment, testing and screening, sealing and packaging, and irradiation sterilization. The coordinated steps of each step enable precise control of feed particle size, optimization of water stability, and compliance with microbial indicators.

[0015] The ingredient mixing process employs a single-shaft paddle mixer to batch and mix the raw materials to be pulverized, resulting in a mixture. The raw materials to be pulverized are preferably aquatic animal protein, selected from one or more of fish meal and shrimp meal. Furthermore, the coefficient of variation of the mixing uniformity of the mixer is ≤5%, providing a stable material basis for subsequent processing steps to obtain a uniformly composed mixture.

[0016] The segmented pulverization process employs a mechanical ultrafine pulverizer and an airflow pulverizer to perform two-stage pulverization of the mixture obtained from the batching and mixing process, thereby obtaining pulverized material. Specifically, the mechanical ultrafine pulverizer first performs pulverization, controlling the fan frequency at 44–49 Hz, the grading frequency at 50–60 Hz, the main unit frequency at 48–55 Hz, the feeding frequency at 11–15 Hz, and the pulverization temperature below 78℃, processing the material particle size to D90≤38μm. Then, the airflow pulverizer performs deep pulverization, controlling the air source pressure at 0.8 MPa, the fan frequency at 37–45 Hz, the grading frequency at 60–95 Hz, and the feeding frequency at 35–48 Hz, further processing the material particle size to D90≤23μm. At this pulverized particle size, various raw materials in the shrimp feed formulation can be fully combined, resulting in uniform and stable nutrition, and the particle size can be controlled. This two-stage progressive pulverization achieves sufficient refinement of raw material particles, improving nutritional uniformity and particle size control stability.

[0017] The secondary mixing process is the same as the ingredient mixing process, both using a single-shaft paddle mixer. In this secondary mixing process, the pulverized material obtained from the segmented pulverizing process is mixed with one or more of the following: high-fat raw materials, heat-sensitive raw materials, liquid raw materials, and paste-like raw materials, to obtain the material to be granulated. The coefficient of variation for mixing uniformity is ≤5%, ensuring uniform mixing of the raw material components and forming a granulated material suitable for subsequent granulation processes. Preferably, the high-fat raw material can be egg yolk powder, the heat-sensitive raw material can be vitamin C, and the liquid paste-like raw material can be fish oil.

[0018] The wet granulation process utilizes a wet granulator, where the material to be granulated is subjected to wet granulation at ambient temperature and pressure. Under the mechanical action of the binder and the wet granulator, the ultrafine powder material collides and combines with each other, forming wet granules with uniform texture and particle size that meet the requirements. The binder is selected from one or more of starch, pregelatinized starch, gelatin, dextrin, alginate, and sodium carboxymethyl cellulose. The binder concentration is controlled at 0.2–3%, and the binder addition amount is 0.5–5%. The stirring paddle speed of the wet granulator is adjusted to 60–170 rpm, the granulation blade speed to 800–2000 rpm, and the spray pressure to 0.05–0.6 MPa. These parameters are used to regulate the operating parameters of the wet granulator to ensure uniform particle formation and complete preservation of heat-sensitive nutrients in the raw materials, ultimately yielding wet granules.

[0019] The fluidized bed drying process uses fluidized bed drying equipment to dry wet particles. The inlet air temperature is controlled at 50-75℃, the material temperature at 40-60℃, the inlet air volume at 10-17 m³ / min, the fan speed at 1700-2500 rpm, and the exhaust air temperature at less than 60℃. The material is dried to a moisture content of less than 10%. The mild and controllable drying conditions preserve the nutrients in the raw materials and stabilize the moisture content of the material, thus obtaining dried material.

[0020] The fluidized bed treatment process also utilizes fluidized bed equipment to process the dried materials. This process sequentially completes fat spraying and coating within the fluidized bed to obtain micro-coated compound feed. The coating weight gain is controlled at 0.5–5% in this process. Furthermore, one or more of the following materials are used for fat spraying and coating: fish oil, phospholipid oil, gelatin, corn gluten, alginate, cellulose derivatives, stearic acid, and glyceryl monostearate. Continuous spraying and coating operations improve the stability of feed pellets in water, thereby reducing nutrient loss. Further, the inlet air temperature during the coating stage is 53–68℃, the inlet air volume is 12–17 m³ / min, the fan speed is 2000–2800 rpm, and the atomization pressure is 0.05–0.15 MPa.

[0021] The testing and screening process uses a rapid moisture analyzer to test the moisture content of the micro-encapsulated feed and a laser particle size analyzer to test the particle size. Based on the test results, the micro-encapsulated feed is physically screened to remove particles that do not meet the size and moisture requirements. Micro-encapsulated shrimp feed with a moisture content ≤10% and a particle size D90 <130μm is separated and obtained. By combining testing and screening, the particle size and moisture content of the feed are precisely controlled to ensure that the feed is suitable for the feeding needs of mysid shrimp.

[0022] The sealing and packaging process involves filling sealed containers with micro-encapsulated shrimp feed for mysids that meets the testing requirements. An oxygen absorber is then added to the sealed containers to control the residual oxygen level below 0.1%, resulting in the finished micro-encapsulated shrimp feed for mysids. Preferably, tin cans are used for filling and sealing. Maintaining a low-oxygen environment inside the packaging by adding an oxygen absorber inhibits microbial growth, ensuring stable and controllable feed quality. Furthermore, production is not affected by seasons, ensuring stable and healthy development of seedlings and addressing the problems of insufficient live feed and the potential for pathogenic microorganisms.

[0023] The irradiation sterilization process uses gamma irradiation to sterilize the sealed and packaged shrimp feed, controlling the irradiation dose to be 3–16 kGy, so that the total bacterial count of the finished product does not exceed 1.0 × 10⁻⁶. 4 A cfu / g ratio can reduce the microbial content inside feed, improve feed hygiene standards, and thus ensure the safety of feed feeding.

[0024] To verify the effectiveness of this process in controlling the nutrient retention and hygiene indicators of the finished product, a third-party testing agency was commissioned to test the finished product. The test data are shown in Tables (1) and (2) below:

[0025] Table (1)

[0026] Table (2)

[0027] As shown in Tables (1) and (2) above, key nutritional indicators such as crude protein, crude fat, and lysine all meet the standard limits, indicating that the ambient temperature wet granulation and low-temperature fluidized bed drying processes of this technology effectively retain the heat-sensitive and easily lost nutrients in the raw materials. The two-stage crushing and two-stage mixing processes ensure the uniform distribution of nutrients in the finished product. The moisture content of the finished product is stably controlled between 3.5% and 3.7%, which is far below the moisture limit set by the process, indicating that the fluidized bed drying process can accurately control the moisture content of the material, providing a guarantee for the storage stability of the finished product. The contents of heavy metals such as lead, total arsenic, mercury, and cadmium all meet the standard limits, and mycotoxins such as aflatoxin B1 and deoxynivalenol are not detected, indicating that the clean production environment of this process effectively controls the introduction of external pollutants. Salmonella was not detected, Escherichia coli count was extremely low, and mold count was at a low level. This indicates that the gamma irradiation sterilization and sealing packaging process effectively killed harmful microorganisms in the feed, inhibited microbial growth during storage, and ensured the hygienic safety of the feed. The above test results show that the micro-encapsulated shrimp feed for mysids produced using this process meets all relevant standard requirements, verifying the stability and reliability of the process. This feed can provide mysids with a nutrient-retaining, moisture-controlled, and hygienic feed product.

[0028] Furthermore, to verify the effect of irradiation sterilization on microbial control, microbial counting tests were conducted on samples that were not irradiated and those irradiated with different doses of gamma, according to the Microbial Limit Test Methods for Non-sterile Products in Part IV of the 2025 Edition of the Pharmacopoeia of the People's Republic of China. The specific test results are shown in Table (3) below:

[0029] Table (3)

[0030] As shown in Table (3) above, the total number of molds and yeasts in the unirradiated sample and each irradiated sample was <10 cfu / g. The total number of aerobic bacteria in the unirradiated sample was relatively high. After irradiation with gamma rays of 3 kGy, 6 kGy, 9 kGy and 15 kGy, the total number of aerobic bacteria gradually decreased with the increase of irradiation dose. After irradiation with 15 kGy, the total number of aerobic bacteria dropped to <10 cfu / g, which fully proves that gamma ray irradiation can effectively reduce the total number of aerobic bacteria in the product and achieve reliable microbial control.

[0031] In summary, the production process of this invention employs a step-by-step mixing process involving ingredient mixing and secondary mixing. First, the raw materials to be pulverized are premixed uniformly, laying a homogeneous foundation for fine pulverization. Then, the pulverized material is mixed a second time with high-fat, heat-sensitive, liquid, and paste-like raw materials. This avoids loss and denaturation of heat-sensitive and liquid raw materials during the pulverization process and ensures a uniform distribution of all ingredients without segregation, significantly improving the nutritional uniformity and batch stability of the feed. Furthermore, by utilizing ambient temperature and pressure granulation, low-temperature drying, and post-coating processes, heat-sensitive nutrients are effectively added and retained, ensuring a balanced nutritional profile in the product. By coating the feed, its stability in water is improved, making it less likely to cloud the water. This effectively improves the aquatic aquaculture environment and reduces feed waste. Furthermore, the entire process, from raw materials to production and then to bottling and sterilization, is strictly controlled to ensure consistent and stable product quality free of pathogens during industrial production. This allows for mass production to meet market demands and consistently produces micro-coated compound feed with a particle size D90 < 130 μm, suitable for the feeding needs of shrimp during the mysid stage. This improves the quality and survival rate of shrimp larvae, providing technical support and reference for the production of mysid feed.

[0032] The above are merely specific embodiments of the present invention, but the design concept of the present invention is not limited thereto. Any non-substantial modifications made to the present invention using this concept shall be considered as infringing upon the protection scope of the present invention.

Claims

1. A production process for a micro-encapsulated shrimp compound feed during the mysid stage, characterized in that, The production process includes the following steps: Ingredient mixing: The raw materials to be crushed are batched and mixed to obtain a mixture. Segmented pulverization: The mixture is first ultra-fine pulverized to a particle size D90≤38μm, and then air-jet pulverized to a particle size D90≤23μm to obtain pulverized material; Secondary mixing: The pulverized material is mixed with one or more of the following: high-fat raw materials, heat-sensitive raw materials, liquid and paste-like raw materials, to obtain the material to be granulated; Wet granulation: The material to be granulated is subjected to wet granulation at room temperature and pressure to obtain wet granules; Fluidized bed drying: The wet particles are subjected to fluidized bed drying, with the inlet air temperature controlled at 50-75℃ and the material temperature at 40-60℃, until the material moisture content is <10%, to obtain the dried material; Fluidized bed treatment: The dried material is subjected to fat spraying and coating treatment in a fluidized bed in sequence, and the coating weight gain is 0.5-5%, to obtain micro-coated compound feed; Testing and screening: Moisture and particle size of micro-coated compound feed are tested to control material moisture ≤10% and particle size D90 <130μm; Sealed packaging: The sieved shrimp feed is filled into sealed containers, and an oxygen absorber is added to ensure that the residual oxygen content in the container is less than 0.1%, thus obtaining packaged feed; Irradiation sterilization: The packaged feed is sterilized by gamma irradiation to obtain the finished product of micro-encapsulated shrimp compound feed for mysid shrimp.

2. The production process of a micro-encapsulated shrimp compound feed for mysid shrimp as described in claim 1, characterized in that, The ingredient mixing and the secondary mixing are carried out using a single-shaft paddle mixer, and the coefficient of variation of the mixing uniformity is ≤5%.

3. The production process of a micro-encapsulated shrimp compound feed for mysid shrimp as described in claim 1, characterized in that, In the segmented pulverization, the parameters for ultrafine pulverization are: fan frequency 44-49Hz, grading frequency 50-60Hz, main unit frequency 48-55Hz, feeding frequency 11-15Hz, and pulverization temperature <78℃; the parameters for airflow pulverization are: air source pressure 0.8MPa, fan frequency 37-45Hz, grading frequency 60-95Hz, and feeding frequency 35-48Hz.

4. The production process of a micro-encapsulated shrimp compound feed for mysids as described in claim 1, characterized in that, In the wet granulation process, the binder used is selected from one or more of starch, pregelatinized starch, gelatin, dextrin, alginate, and sodium hydroxymethyl cellulose, and the binder concentration is 0.2-3% and the addition amount is 0.5-5%; the stirring paddle speed is 60-170 rpm, the granulation blade speed is 800-2000 rpm, and the spraying pressure is 0.05-0.6 MPa.

5. The production process of a micro-encapsulated shrimp compound feed for mysid shrimp as described in claim 1, characterized in that, In the fluidized bed drying process, the inlet air volume is 10-17 m³ / min, the fan speed is 1700-2500 rpm, and the exhaust air temperature is <60℃.

6. The production process of a micro-encapsulated shrimp compound feed for mysid shrimp as described in claim 1, characterized in that, In the fluidized bed treatment, the materials used for the fat spraying and coating treatment are selected from one or more of fish oil, phospholipid oil, gelatin, corn gluten, alginate, cellulose derivatives, stearic acid, and glyceryl monostearate.

7. The production process of a micro-encapsulated shrimp compound feed for mysids as described in claim 1 or 6, characterized in that, The inlet air temperature during the coating process is 53–68℃, the inlet air volume is 12–17 m³ / min, the fan speed is 2000–2800 rpm, and the atomization pressure is 0.05–0.15 MPa.

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