A method for improving the sinking rate of black soldier fly larvae and its application

Abstract

The present invention belongs to the technical field of aquaculture. The present invention discloses a method for improving the sinking rate of black soldier fly larvae, which method comprises: S1: preparing an osmotic active solution; S2: water penetration, immersing the black soldier fly larvae in the osmotic active solution; S3: preparing a viscous coating solution and immersing the black soldier fly larvae therein; S4: putting the black soldier fly larvae into a stirring drying oven, adding a weight-increasing powder and stirring and heating; S5: freezing, freezing the dried black soldier fly larvae; S6: putting the frozen black soldier fly larvae into a stirring kettle for stirring to obtain the target black soldier fly larvae. The present invention extracts the water in the black soldier fly larvae through osmosis and attaches diatomaceous earth to the surface of the black soldier fly larvae to increase the relative density, thereby increasing the sinking rate of the black soldier fly larvae. By attaching diatomaceous earth to the surface of the black soldier fly larvae, the present invention can also prevent the black soldier fly larvae from caking during freezing.

Description

Technical Field

[0001] The present invention belongs to the technical field of aquaculture, and specifically relates to a method for improving the sinking rate of black soldier fly larvae and its application. Background Art

[0002] Hairy crabs are important aquaculture varieties in China, and their quality and yield are directly related to the economic benefits of farmers. As a high-protein and nutrient-rich feed, black soldier fly larvae are widely used in the feeding of hairy crabs. However, in the actual process of using black soldier fly larvae to feed hairy crabs, it is found that some of the frozen black soldier fly larvae will float on the water surface, making it inconvenient for hairy crabs to feed, and affecting their growth rate and quality. Moreover, too many black soldier fly larvae floating on the water surface will cause problems such as the formation of an oil film on the water surface, water quality deterioration, and a decrease in dissolved oxygen. The floating black soldier fly larvae will also become a breeding ground for pathogenic microorganisms. Black soldier fly larvae with a high sinking rate can reduce the accumulation of feed on the water surface, help maintain a good water quality environment, and are beneficial to the healthy growth of hairy crabs. The black soldier fly larvae sinking to the bottom of the water can also reduce the risk of the spread of pathogenic microorganisms in the water body, and help maintain the biological safety of the aquaculture environment. On the other hand, when transporting black soldier fly larvae, in order to ensure the shelf life of black soldier fly larvae, they need to be frozen. The frozen black soldier fly larvae are prone to caking. When using the caked frozen black soldier fly larvae to feed hairy crabs, it will be difficult for hairy crabs to feed. When naturally thawing the caked black soldier fly larvae, on the one hand, it takes a lot of time, and on the other hand, it will cause the corruption of black soldier fly larvae in hot weather. Therefore, how to improve the sinking rate of frozen larvae and how to prevent the frozen black soldier fly larvae from caking have become urgent problems to be solved. Summary of the Invention

[0003] In order to solve the deficiencies of the prior art, the present application discloses a method for improving the sinking rate of black soldier fly larvae and its application, which can improve the sinking rate of black soldier fly larvae and prevent the frozen black soldier fly larvae from caking.

[0004] The present invention discloses a method for improving the sinking rate of black soldier fly larvae, which includes: S1: Prepare an osmotic active solution. Take a certain amount of osmotic agent, mix the osmotic agent with water, and stir evenly until the osmotic agent is completely dissolved in water to form an osmotic active solution. S2: Water penetration. Put the black soldier fly larvae into the osmotic active solution for soaking. After soaking for a certain time, use a sieve to fish out the black soldier fly larvae. S3: Prepare a viscous coating solution. Take a certain amount of viscous agent and coating agent and mix them with water, stir evenly until the viscous agent and coating agent are completely dissolved in water to form a viscous coating solution. Put the black soldier fly larvae into the viscous coating solution for soaking. After soaking for a certain time, use a sieve to fish out the black soldier fly larvae. S4: Drying and powder sprinkling. Put the black soldier fly larvae into a stirring drying oven for stirring and heating. After drying for a certain time, add a weight-increasing powder and continue stirring and drying. After continuing to dry for a certain time, obtain dried black soldier fly larvae. S5: Freezing. Freeze the dried black soldier fly larvae. S6: Put the frozen black soldier fly larvae into a stirring kettle for stirring, and obtain the target black soldier fly larvae after stirring. Among them, the viscous agent is at least one of starch or guar gum powder. Among them, the coating agent is at least one of chitosan or gelatin. Among them, the weight-increasing powder is at least one of calcium carbonate, talcum powder or diatomaceous earth.

[0005] Further, in S1, the osmotic agent is at least one of salt or organic matter.

[0006] Further, the salt is at least one of sodium chloride or sodium sulfate, and the organic matter is at least one of sucrose or urea.

[0007] Further, in S1, the osmotic active solution is a sodium chloride solution, and the concentration of the sodium chloride solution is greater than or equal to 8% and less than or equal to 12%.

[0008] Further, when putting the black soldier fly larvae into the osmotic active solution for soaking in S2, raise the temperature of the osmotic active solution. The temperature range of the osmotic active solution is greater than or equal to 40°C and less than or equal to 60°C. The soaking time of the black soldier fly larvae in the osmotic active solution in S2 is greater than or equal to 2 hours and less than or equal to 4 hours.

[0009] Further, the soaking time of the black soldier fly larvae in the viscous coating solution in S3 is greater than or equal to 1 hour and less than or equal to 1.5 hours. The concentration of the viscous agent in the viscous coating solution in S3 is 0.8%-1.2%, and the concentration of the coating agent in the viscous coating solution in S3 is 0.8%-1.2%.

[0010] Further, in S4, the rotation speed of the stirring drying oven is set to be greater than or equal to 15 r / min and less than or equal to 30 r / min, the temperature inside the stirring drying oven is set to be greater than or equal to 40 °C and less than or equal to 60 °C, the mesh number of the weight-increasing powder in S4 is greater than or equal to 100 mesh and less than or equal to 400 mesh, and the weight of the weight-increasing powder in the stirring drying oven in S4 is 5% to 15% of the weight of the black soldier fly larvae in the stirring drying oven.

[0011] Further, in S5, the freezing temperature of the black soldier fly larvae is less than or equal to -18 °C, and the freezing time is greater than or equal to 1 h and less than or equal to 2 h.

[0012] The present invention also discloses an application for improving the sinking rate of black soldier fly larvae, which uses the black soldier fly larvae prepared by any one of the methods for improving the sinking rate of black soldier fly larvae described above to feed Chinese mitten crabs.

[0013] Beneficial effects of the present invention:

[0014] First, the black soldier fly larvae of the present invention are immersed in the osmotic active solution. Through the osmotic effect, the water content in the black soldier fly larvae is reduced, so that the relative density of the black soldier fly larvae increases, which helps the black soldier fly larvae to sink in water and increases the sinking rate. After the black soldier fly larvae are immersed in the osmotic active solution, the black soldier fly larvae are immersed in the viscous coating solution. The adhesive component and the coating component in the viscous coating solution adhere to the surface of the black soldier fly larvae in the viscous coating solution. Among them, the adhesive can form a viscous adhesive film on the surface of the black soldier fly larvae. The adhesive film can help fix diatomaceous earth on the surface of the black soldier fly larvae. On the one hand, the coating agent is used to enhance the binding force between the adhesive and the surface of the black soldier fly larvae, so that the adhesive is more firmly fixed to the surface of the black soldier fly larvae. On the other hand, the coating agent can form a protective film on the surface of the black soldier fly larvae to prevent the erosion and damage of the black soldier fly larvae by external factors. The weight-increasing powder is evenly mixed with the black soldier fly larvae through stirring in the stirring drying oven. The adhesive and the coating agent on the surface of the black soldier fly larvae bond the weight-increasing powder to the surface of the black soldier fly larvae. The density of the weight-increasing powder is greater than the density of the black soldier fly larvae and greater than the density of water, and the weight-increasing powder has a large specific surface area and pore structure, which can form a certain viscosity in the animal digestive tract, help to extend the digestion time of the feed, and improve the absorption efficiency of nutrients. After drying, the black soldier fly larvae are frozen. When freezing, because the weight-increasing powder is adhered to the surface of the black soldier fly larvae, the black soldier fly larvae do not contact each other at this time, so that the probability of agglomeration of the black soldier fly larvae during freezing is greatly reduced. When the black soldier fly larvae are completely frozen, a small part of the agglomerated black soldier fly larvae is separated by using a stirring kettle to increase the overall uniformity of the black soldier fly larvae. The black soldier fly larvae of the present application can have a high sinking rate through the above method, and the agglomeration between the black soldier fly larvae is reduced by the weight-increasing powder on the surface of the black soldier fly larvae and stirring after freezing. Description of the drawings

[0015] Figure 1 This is a flowchart of the method for improving the sinking rate of black soldier fly larvae in the embodiments of this application. Specific embodiments

[0016] In order to enable those skilled in the art to better understand the solution of the present invention, the technical solutions in the specific embodiments of the present invention will be clearly and completely described below.

[0017] The present invention discloses a method for improving the sinking rate of black soldier fly larvae, which includes: S1: Prepare a permeation-active solution. Take a certain amount of permeation agent, mix the permeation agent with water, and stir evenly until the permeation agent is completely dissolved in water to form a permeation-active solution. The permeation-active solution is used to remove part of the moisture inside the black soldier fly larvae through osmosis, thereby increasing the relative density of the black soldier fly larvae. S2: Moisture permeation. Put the black soldier fly larvae into the permeation-active solution for soaking. After soaking for a certain time, use a sieve to fish out the black soldier fly larvae. After soaking for a period of time, due to the relationship of osmotic pressure, part of the moisture of the black soldier fly larvae will be separated, reducing part of the weight of the black soldier fly larvae, increasing the relative density of the black soldier fly larvae, and increasing the sinking rate of the black soldier fly larvae. S3: Configure a viscous coating solution. Take a certain amount of viscous agent and coating agent and mix them with water, and stir evenly until the viscous agent and coating agent are completely dissolved in water to form a viscous coating solution. Put the black soldier fly larvae into the viscous coating solution for soaking. After soaking for a certain time, use a sieve to fish out the black soldier fly larvae. The viscous agent can adhere to the surface of the black soldier fly larvae to increase the surface viscosity of the black soldier fly larvae. When the black soldier fly larvae are soaked, the viscous agent will adhere to the surface of the black soldier fly larvae to form a viscous viscous agent film. The viscous agent film can firmly bond other molecules. The coating agent has film-forming properties. On the one hand, it is used to further increase the viscosity of the viscous agent and increase the firmness of the bonding between the viscous agent and the black soldier fly larvae. On the other hand, when the black soldier fly larvae are bonded with the weight-increasing powder subsequently, the coating agent can wrap and cover the weight-increasing powder to reduce the interference of the outside world on the weight-increasing powder. S4: Drying and powder spraying. Put the black soldier fly larvae into a stirring drying oven for stirring and heating. After drying for a certain time, add the weight-increasing powder and continue stirring and drying. After continuing to dry for a certain time, dried black soldier fly larvae are obtained. First, drying for a certain time is to dry a large amount of moisture on the surface of the black soldier fly larvae, but there is still a small amount of moisture on the surface of the black soldier fly larvae. At this time, add the weight-increasing powder to the stirring drying oven for stirring and drying. The weight-increasing powder is firmly bonded to the surface of the black soldier fly larvae under the action of moisture, viscous agent and coating agent. After stirring for a certain time, the weight-increasing powder and the black soldier fly larvae are evenly mixed. At this time, continue stirring and drying until the black soldier fly larvae are dry. The weight-increasing powder can, on the one hand, increase the weight of the black soldier fly larvae, increase the relative density of the black soldier fly larvae by increasing the weight, thereby increasing the sinking rate of the black soldier fly larvae. On the other hand, when the black soldier fly larvae are frozen, the weight-increasing powder can separate the black soldier fly larvae from each other to prevent the black soldier fly larvae from bonding and caking due to freezing. S5: Freezing. Freeze the dried black soldier fly larvae. S6: Put the frozen black soldier fly larvae into a stirring kettle for stirring, and the target black soldier fly larvae are obtained after stirring. Among them, the viscous agent is at least one of starch or guar gum powder. Among them, the coating agent is at least one of chitosan or gelatin. Among them, the weight-increasing powder is at least one of calcium carbonate, talcum powder or diatomaceous earth.The encapsulating agent is preferably chitosan. After the surface of the black soldier fly larvae is adhered with the weight-increasing powder by the adhesive film, the weight of the black soldier fly larvae is increased. However, if the black soldier fly larvae undergo relatively intense friction or vibration, etc., the weight-increasing powder on the outer surface of the black soldier fly larvae may fall off, affecting the sinking rate of the black soldier fly larvae. In this application, after the weight-increasing powder is adhered by the adhesive film, the weight-increasing powder is encapsulated through the action of the encapsulating agent to prevent the weight-increasing powder from being interfered by the outside world. The chitosan molecules in the encapsulating agent have good film-forming properties. Chitosan is a linear polymer, and its molecular chain contains a large number of amino groups. These amino groups can interact through hydrogen bonds and form hydrogen bonds with water molecules, promoting the close arrangement of molecules during the drying process of the solution to form a continuous and stable film. When chitosan is on the surface of the black soldier fly larvae and gradually dries out and loses water, the chitosan molecules gradually approach and self-assemble to form a covering film to protect the black soldier fly larvae and prevent the weight-increasing powder on the outer surface of the black soldier fly larvae from falling off. The chitosan molecular film has stability and durability, enabling the weight-increasing powder on the outer layer of the black soldier fly larvae not to fall off when the black soldier fly larvae undergo relatively intense friction or vibration. First, the black soldier fly larvae are put into the osmotic active solution for soaking. Since the osmotic pressure of the osmotic active solution is higher than the osmotic pressure of the body fluid of the black soldier fly larvae, during the soaking process, the water in the body fluid of the black soldier fly larvae will permeate from the inside of the black soldier fly larvae to the outside to try to achieve the balance of the internal and external osmotic pressures. This will cause the water content in the black soldier fly larvae to decrease and the relative density to increase, which helps the black soldier fly larvae to sink in water and increases the sinking rate. After the black soldier fly larvae are soaked in the osmotic active solution, the black soldier fly larvae are put into the viscous encapsulating solution for soaking. The adhesive component and the encapsulating agent component in the viscous encapsulating solution adhere to the surface of the black soldier fly larvae in the viscous encapsulating solution. Among them, the adhesive can form an adhesive film with adhesiveness on the surface of the black soldier fly larvae, and the adhesive film can help fix diatomaceous earth on the surface of the black soldier fly larvae. On the one hand, the encapsulating agent is used to enhance the binding force between the adhesive and the surface of the black soldier fly larvae, making the adhesive more firmly fixed to the surface of the black soldier fly larvae. On the other hand, the encapsulating agent can form a protective film on the surface of the black soldier fly larvae to prevent the erosion and damage of the black soldier fly larvae by external factors. After the black soldier fly larvae are soaked in the viscous encapsulating solution for a certain period of time, they are fished out with a sieve, and the black soldier fly larvae are put into a stirring drying box for stirring and heating. After heating for a certain period of time, when the moisture content on the surface of the black soldier fly larvae is reduced to a certain degree, the weight-increasing powder is added into the stirring drying box, and stirring continues until the surface of the black soldier fly larvae is dry.The weight gain powder is evenly mixed with black soldier fly larvae in a stirring and drying oven. The adhesive and coating agent on the surface of the black soldier fly larvae bond the weight gain powder to the surface of the black soldier fly larvae. The density of the weight gain powder is greater than that of the black soldier fly larvae and greater than that of water, and the weight gain powder has a large specific surface area and pore structure, which can form a certain viscosity in the animal digestive tract, help extend the digestion time of the feed, and improve the absorption efficiency of nutrients. By bonding the weight gain powder on the surface of the black soldier fly larvae, on the one hand, it can increase the relative density of the black soldier fly larvae, thereby increasing the sinking rate of the black soldier fly larvae, and on the other hand, it can make the black soldier fly larvae easier to be absorbed as feed in the animal body. After drying, the black soldier fly larvae are frozen. When freezing, because the weight gain powder is bonded to the surface of the black soldier fly larvae, the black soldier fly larvae do not contact each other at this time, so that the probability of agglomeration between the black soldier fly larvae is greatly reduced when freezing. When the black soldier fly larvae are completely frozen, a small part of the agglomerated black soldier fly larvae is separated by a stirring kettle to increase the overall uniformity of the black soldier fly larvae. The black soldier fly larvae of the present application can have a high sinking rate through the above method, and the agglomeration between the black soldier fly larvae is reduced by the weight gain powder on the surface of the black soldier fly larvae and stirring after freezing.

[0018] As an implementation manner, the penetrant in S1 is at least one of salts or organic substances.

[0019] As an implementation manner, the salt is at least one of sodium chloride or sodium sulfate, and the organic substance is at least one of sucrose or urea. The above materials are relatively easy to obtain and non-toxic, and the osmotic pressure of the osmotic active solution is greater than that of the internal body fluid of the black soldier fly larvae, which can extract the water in the black soldier fly larvae, increase the relative density of the black soldier fly larvae, and improve the sinking rate.

[0020] As an implementation manner, the osmotic active solution in S1 is a sodium chloride solution, and the concentration of the sodium chloride solution is greater than or equal to 8% and less than or equal to 12%. Sodium chloride is the most common osmotic active solution, and the material is relatively easy to obtain. The concentration of the sodium chloride solution determines the effect of extracting water from the black soldier fly larvae and affects the effect of increasing the relative density of the black soldier fly larvae. When the concentration of the sodium chloride solution is less than 8%, it is difficult for the sodium chloride solution to extract more water from the black soldier fly larvae and it is difficult to increase the relative density of more black soldier fly larvae. When the concentration of the sodium chloride solution is greater than 12%, the sodium chloride solution not only extracts the water in the black soldier fly larvae but also extracts the nutrients in the body fluid of the black soldier fly larvae, affecting the nutritional value of the black soldier fly larvae as feed. In summary, the concentration of the sodium chloride solution in the present application is set to be greater than or equal to 8% and less than or equal to 12%. Further, the concentration of the sodium chloride solution is greater than or equal to 9% and less than or equal to 11%. Further still, the concentration of the sodium chloride solution is 10%.

[0021] As an implementation method, when S2 soaks the black soldier fly larvae in the osmotic active solution, the temperature of the osmotic active solution is increased, and the temperature range of the osmotic active solution is greater than or equal to 40 °C and less than or equal to 60 °C. The soaking time of the black soldier fly larvae in the osmotic active solution in S2 is greater than or equal to 2 hours and less than or equal to 4 hours. The temperature range of the osmotic active solution is greater than or equal to 40 °C and less than or equal to 60 °C. The appropriate temperature can accelerate the osmosis effect of the water in the black soldier fly larvae into the osmotic active solution, reduce the osmosis time. The soaking time of the black soldier fly larvae in the osmotic active solution has a certain impact on the black soldier fly larvae. If the soaking time is too short, incomplete osmosis will result in a relatively small effect of increasing the relative density of the black soldier fly larvae. If the soaking time is too long, the osmotic active solution will erode the black soldier fly larvae.

[0022] As an implementation method, the soaking time of the black soldier fly larvae in the viscous wrapping solution in S3 is greater than or equal to 1 hour and less than or equal to 1.5 hours. The concentration of the viscous agent in the viscous wrapping solution in S3 is 0.8%-1.2%, and the concentration of the wrapping agent in the viscous wrapping solution in S3 is 0.8%-1.2%.

[0023] As an implementation method, the rotation speed of the stirring drying oven in S4 is set to be greater than or equal to 15 r / min and less than or equal to 30 r / min, the temperature inside the stirring drying oven is set to be greater than or equal to 40 °C and less than or equal to 60 °C. The mesh number of the weight-increasing powder in S4 is greater than or equal to 100 mesh and less than or equal to 400 mesh. The weight of the weight-increasing powder in the stirring drying oven in S4 is 1% to 5% of the weight of the black soldier fly larvae in the stirring drying oven.

[0024] As an implementation method, the freezing temperature of the black soldier fly larvae in S5 is less than or equal to -18 °C, and the freezing time is greater than or equal to 1 h and less than or equal to 2 h.

[0025] The present invention discloses an application for improving the sinking rate of black soldier fly larvae. The application for improving the sinking rate of black soldier fly larvae uses a method for improving the sinking rate of black soldier fly larvae as described in any one of the above.

[0026] Example:

[0027] Example 1: Preparation of frozen black soldier fly larvae

[0028] S1: Prepare the osmotic active solution. Take 2000 g of sodium chloride, mix 2000 g of sodium chloride with 20000 ml of water, and stir evenly until the sodium chloride is completely dissolved in the water to form a sodium chloride solution;

[0029] S2: Pretreat 2000 black soldier fly larvae. Rinse the black soldier fly larvae with deionized water, and then put the rinsed black soldier fly larvae into the sodium chloride solution for soaking. The temperature of the sodium chloride solution is 50 °C, and the soaking time is 3 h;

[0030] S3: Prepare a viscous wrapping solution containing 1% starch and 1% chitosan. Immerse the black soldier fly larvae in the viscous wrapping solution for 1 h, and then scoop out the immersed black soldier fly larvae using a sieve.

[0031] S4: Put the black soldier fly larvae into a stirring drying oven for stirring and heating. Set the rotation speed of the stirring drying oven to 20 r / min, set the temperature inside the stirring drying oven to 50 °C, and add diatomaceous earth with a mesh size of 300 when the moisture content on the surface of the black soldier fly larvae is 1%. The weight of the diatomaceous earth is 10% of the weight of the black soldier fly larvae.

[0032] S5: Freeze the dried black soldier fly larvae at -20 °C for 1.5 h.

[0033] S6: Put the frozen black soldier fly larvae into a stirring kettle for stirring, and obtain the target black soldier fly larvae after stirring evenly.

[0034] Example 2: Preparation of frozen black soldier fly larvae

[0035] The difference from Example 1 is that 1600 g of sodium chloride is used in S1, and the others are the same as in Example 1.

[0036] Example 3: Preparation of frozen black soldier fly larvae

[0037] The difference from Example 1 is that the concentration of starch in S3 is 0.8%, and the others are the same as in Example 1.

[0038] Example 4: Preparation of frozen black soldier fly larvae

[0039] The difference from Example 1 is that the weight of the diatomaceous earth in S5 is 8% of the weight of the black soldier fly larvae, and the others are the same as in Example 1.

[0040] Example 5: Preparation of frozen black soldier fly larvae

[0041] The difference from Example 1 is that the concentration of chitosan in S3 is 0.8%, and the others are the same as in Example 1.

[0042] Comparative Example 1: Preparation of frozen black soldier fly larvae

[0043] The difference from Example 1 is that starch is not used to soak the black soldier fly larvae in S3, and the others are the same as in Example 1.

[0044] Comparative Example 2: Preparation of frozen black soldier fly larvae

[0045] The difference from Example 1 is that diatomaceous earth is not added to the stirring drying oven in S4, and the others are the same as in Example 1.

[0046] Comparative Example 3: Preparation of frozen black soldier fly larvae

[0047] Differing from Example 1, chitosan was not used in S63, and the rest was the same as in Example 1.

[0048] Comparative Example 4: Preparation of frozen black soldier fly larvae

[0049] S1: Pretreat 2000 black soldier fly larvae, rinse the black soldier fly larvae with deionized water, and dry the black soldier fly larvae after rinsing.

[0050] S2: Put the dried black soldier fly larvae into a stirring kettle, set the rotation speed of the stirring kettle to 20 r / min, set the stirring temperature to -20 °C, perform freezing treatment while stirring, and stop stirring after 1.5 h of freezing and stirring to obtain frozen black soldier fly larvae.

[0051] Data analysis:

[0052] Put 200 frozen black soldier fly larvae prepared in Examples 1-5 and Comparative Examples 1-3 into water respectively, and calculate the sinking rate of the frozen black soldier fly larvae. The calculation results are shown in Table 1 below.

[0053]

[0054] As can be seen from Table 1:

[0055] As can be seen from Examples 1-5, within a certain concentration range, the concentrations of sodium chloride solution, starch solution, diatomite suspension, and chitosan solution affect the final sinking rate of black soldier fly larvae. Generally, as the concentrations of the above test solutions increase, the sinking rate of black soldier fly larvae increases accordingly.

[0056] As can be seen from Example 1 and Comparative Examples 1-4, when the starch solution is not used, the viscosity on the surface of black soldier fly larvae is lower and less diatomite adheres, resulting in a lower sinking rate of the final black soldier fly larvae. When the diatomite suspension is not used, no other materials adhere to the surface of black soldier fly larvae, and only the osmosis effect increases the sinking rate of black soldier fly larvae, resulting in a lower sinking rate of the final black soldier fly larvae. When the chitosan solution is not used, more diatomite adhered to the surface of black soldier fly larvae is removed by friction during stirring and freezing, resulting in a lower sinking rate of the final black soldier fly larvae. When the method of the present invention is not used, the sinking rate of black soldier fly larvae is the lowest.

[0057] It should be understood that for those of ordinary skill in the art, improvements or changes can be made according to the above description, and all such improvements and changes should fall within the protection scope of the appended claims of the present invention.

Claims

1. A method for improving the water sinking rate of black soldier fly larvae, characterized in that: include: S1: preparing an osmotic active solution, taking a certain amount of osmotic active agent, mixing the osmotic active agent with water, and stirring evenly until the osmotic active agent is completely dissolved in the water to form an osmotic active solution; S2: water penetration, the black soldier fly larvae are immersed in an osmotic active solution, and after a certain period of time, the black soldier fly larvae are fished out using a sieve; S3: preparing a viscous wrapping liquid, taking a certain amount of a viscous agent and a wrapping agent and mixing them with water, stirring evenly until the viscous agent and the wrapping agent are completely dissolved in the water to form a viscous wrapping liquid, and soaking the black soldier fly larvae fished out in step S2 in the viscous wrapping liquid, and after soaking for a certain period of time, using a sieve to fish out the black soldier fly larvae; S4: Drying and powdering, putting the black soldier fly larvae fished out in step S3 into a stirring drying oven for stirring and heating, adding weight-increasing powder after drying for a certain period of time, and continuing to stir and dry, and obtaining dried black soldier fly larvae after continuing to dry for a certain period of time; S5: freezing, freezing the dried black soldier fly larvae; S6: putting the frozen black soldier fly larvae into a stirring tank for stirring, and obtaining target black soldier fly larvae after stirring; Wherein, the viscosity agent is at least one of starch or guar gum powder, Wherein, the encapsulating agent is at least one of chitosan or gelatin; Wherein, the weight-increasing powder is at least one of calcium carbonate, talcum powder or diatomaceous earth.

2. A method for improving the water sinking rate of black soldier fly larvae according to claim 1, characterized in that: The osmotic agent in S1 is at least one of a salt or an organic substance.

3. A method for improving the water sinking rate of black soldier fly larvae according to claim 2, characterized in that: The salt is at least one of sodium chloride and sodium sulfate, and the organic matter is at least one of sucrose and urea.

4. A method for improving the water sinking rate of black soldier fly larvae according to claim 3, characterized in that: The osmotic active solution in S1 is a sodium chloride solution, and the concentration of the sodium chloride solution is greater than or equal to 8% and less than or equal to 12%.

5. A method for improving the water sinking rate of black soldier fly larvae according to claim 1, characterized in that: S2: when the black soldier fly larvae are immersed in the osmotic active solution, the temperature of the osmotic active solution is increased, and the temperature range of the osmotic active solution is greater than or equal to 40° C. and less than or equal to 60° C.; The immersion time of the black soldier fly larvae in the osmotic active solution in S2 is greater than or equal to 2 hours and less than or equal to 4 hours.

6. A method for improving the water sinking rate of black soldier fly larvae according to claim 1, characterized in that: In S3, the immersion time of the black soldier fly larvae in the sticky wrapping liquid is greater than or equal to 1 hour and less than or equal to 1.5 hours; The concentration of the viscous agent in S3 in the viscous wrapping liquid is 0.8%-1.2%; The concentration of the encapsulating agent in the viscous encapsulating liquid in S3 is 0.8%-1.2%.

7. A method for improving the water sinking rate of black soldier fly larvae according to claim 1, characterized in that: In S4, the rotation speed of the stirring drying oven is set to be greater than or equal to 15 r / min and less than or equal to 30 r / min, and the temperature in the stirring drying oven is set to be greater than or equal to 40° C. and less than or equal to 60° C.; The mesh size of the weight-increasing powder in S4 is greater than or equal to 100 mesh and less than or equal to 400 mesh; The weight of the weight-increasing powder in the stirring drying oven in S4 is 5% to 15% of the weight of the black soldier fly larvae in the stirring drying oven.

8. A method for improving the water sinking rate of black soldier fly larvae according to claim 1, characterized in that: In S5, the freezing temperature of the black soldier fly larvae is less than or equal to -18°C, and the freezing time is greater than or equal to 1 hour and less than or equal to 2 hours.

9. An application for improving the water sinking rate of black soldier fly larvae, characterized in that: The black soldier fly larvae prepared by the method for improving the water sinking rate of black soldier fly larvae as described in any one of claims 1 to 8 are used to feed hairy crabs.

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