Method for preparing krill protein

Abstract

The invention relates to a method for preparing krill protein, which comprises the following steps: step 1, crushing: crushing defatted krill powder by using a crusher until the particle size is uniform, the optimal particle size is 120-150 meshes, and the water content in the defatted powder is lower than 10%; step 2, screening: screening different components with 120 to 130 meshes, 130 to 140 meshes and 140 to 150 meshes by using a screen; step 3, mixing: mixing the graded shrimp powder with water according to a certain mass ratio to achieve a wetting effect, and the moisture content after mixing is greater than or equal to 20%; step 4, shell and meat separation: uniformly and slowly adding the wet shrimp powder into a feeding hole of shrimp shell separation equipment, and separating shrimp meat from shrimp shells through the separation equipment; step 5, solid-liquid separation: collecting shrimp powder at a discharge port of the shrimp shell separation equipment and separating water to obtain low-protein and high-fluorine shrimp shells and high-protein and low-fluorine shrimp meat, and recycling the separated water; and step 6, drying and crushing: drying and crushing the shrimp meat part to obtain the edible krill protein.

Description

Technical Field

[0001] The invention relates to the technical field of krill protein production, in particular to a method for preparing krill protein. Background Art

[0002] Antarctic krill is rich in fat and protein, and has a high fluorine content, which is mainly found on its shell. At present, the common practice of deep processing companies is to make whole shrimp powder after catching it in Antarctica, and then transport it back to land to extract krill oil as a raw material for health products. The remaining skimmed powder is mainly used as a feed additive, which makes its high-quality protein value not high. However, because the fluorine content in skimmed powder is high, there is a risk of excessive fluorine intake if it is used directly as food. Therefore, it is necessary to further extract protein from the skimmed powder so that it can be more conveniently used in the food field.

[0003] Because the fluorine in the defatted powder mainly exists in the shrimp shells, as long as the shrimp shells are separated, the protein powder with low fluorine content and high protein content can be obtained. Krill shells are thin and fragile. After preparing shrimp powder on the ship, extracting shrimp oil, desolventizing and drying, most shrimp shells have been completely crushed into fine particles. In the defatted powder, shrimp meat and shells are mixed together. The density difference between shrimp meat particles and shrimp shells is not large enough, and traditional methods such as air separation are difficult to effectively separate.

[0004] In the existing technology, there are two main methods for extracting krill protein from defatted powder. The first method is to use the alkali dissolution and acid precipitation method (Gao Fei et al.; Optimization of Antarctic krill protein extraction conditions, Natural Product Research and Development, 2016, 28: 307-312, 194) (or the method described in the invention patent: CN201910833418.3, a method for extracting Antarctic krill protein): first use NaOH to adjust the pH value of water to alkaline so that the krill protein is dissolved in water, separate and remove insoluble matter (mainly shells), and then use hydrochloric acid to adjust the pH value of the aqueous solution to acidic, so that the protein precipitates out, separates the protein, and then adjusts to neutral, and dries to obtain krill protein. The disadvantage of this method is that it will produce a large amount of wastewater, high cost and unfavorable to the environment.

[0005] The second method is to use an enzymatic hydrolysis method (CN201210029946.1, a method for preparing low-fluorine Antarctic krill hydrolyzed protein powder), using an enzyme preparation to hydrolyze krill protein, dissolve the protein in water, separate the insoluble matter (shrimp shell and unhydrolyzed protein), and then dry the enzymatic hydrolyzate to obtain krill protein. This method is time-consuming and has high processing costs. Summary of the invention

[0006] In view of the shortcomings of the prior art, the object of the present invention is to provide a method for preparing krill protein, which is a simpler physical separation method, reduces processing costs, reduces wastewater and reduces environmental pollution.

[0007] The above-mentioned object of the present invention is achieved through the following technical solutions:

[0008] A method for preparing krill protein comprises the following steps:

[0009] Step 1, crushing, crushing the defatted shrimp powder into a uniform particle size using a crusher, preferably 120-150 mesh, and the moisture content of the defatted powder is less than 10%;

[0010] Step 2, screening, using a sieve to screen into different components of 120-130 mesh, 130-140 mesh, and 140-150 mesh;

[0011] Step 3: Mixing: Mix the graded shrimp powder with water in a certain mass ratio to achieve a wetting effect. After mixing, the moisture content is ≥ 20%;

[0012] Step 4, separating the shell from the meat, adding the wet shrimp powder evenly and slowly into the feed port of the shrimp shell separation device, and separating the shrimp meat from the shrimp shell through the shrimp shell separation device;

[0013] Step 5, solid-liquid separation, collecting shrimp powder at the outlet of the shrimp shell separation device and separating them to obtain low-protein and high-fluoride shrimp shells and high-protein and low-fluoride shrimp meat, and the separated water can be recycled;

[0014] Step 6: Drying and crushing: drying and crushing the shrimp meat to obtain edible krill protein.

[0015] As a further technical solution of the present invention: the defatted shrimp meal is a byproduct remaining after krill oil is extracted from full-fat shrimp meal, and the moisture content of the defatted shrimp meal is ≤10%, and the crude fat content is ≤11%.

[0016] As a further technical solution of the present invention: in step 4, the shrimp shell separation equipment includes an equipment body, a separation cavity for separating shrimp shells and shrimp meat is provided in the equipment body, a separation mechanism is installed in the separation cavity, the separation mechanism divides the separation cavity into a first cavity and a second cavity, a water inlet connected to the separation cavity is provided at one end of the equipment body, and a shrimp meat outlet and a shrimp shell outlet are provided at the other end, the shrimp meat outlet is connected to the first cavity, and the shrimp shell outlet is connected to the second cavity, and a feeding mechanism is provided above one end of the equipment body close to the water inlet.

[0017] As a further technical solution of the present invention: the equipment body comprises a water inlet pipe, a box body, a first water outlet pipe and a second water outlet pipe, the water inlet is arranged at one end of the water inlet pipe, the other end of the water inlet pipe is connected to the box body, and one end of the first water outlet pipe and one end of the second water outlet pipe are respectively connected to one end of the box body away from the water inlet pipe;

[0018] The first cavity is communicated with the interior of the first water outlet pipe, the second cavity is communicated with the interior of the second water outlet pipe, the shrimp meat outlet is arranged at one end of the first water outlet pipe, and the shrimp shell outlet is arranged at one end of the second water outlet pipe.

[0019] As a further technical solution of the present invention: the separation mechanism comprises a partition plate assembly and a lifting mechanism, the partition plate assembly is arranged between the first cavity and the second cavity, and the lifting mechanism is used to drive the partition plate assembly to move up and down in the separation cavity;

[0020] The partition plate assembly includes a sliding plate, a lifting plate and a connecting part, one end of the connecting part is fixedly connected to the connection between the first water outlet pipe and the second water outlet pipe, and the other end is connected to the lifting plate. A lifting mechanism is installed in the equipment body, and the lifting mechanism is transmission-connected to the lifting plate. The lifting mechanism is used to drive the lifting plate to move up and down in the separation chamber.

[0021] As a further technical solution of the present invention: the lifting mechanism includes multiple screws, which are symmetrically distributed on both sides of the separation chamber and threadedly connected to the lifting plate. The multiple screws are driven by a motor to rotate simultaneously so that the lifting plate moves up and down in the separation chamber.

[0022] As a further technical solution of the present invention: two support plates are integrally formed and fixedly connected on both sides of one end of the lifting plate away from the connecting part, and the sliding plate is overlapped on top of the two support plates, and can not only move left and right, but also move up and down with the lifting plate.

[0023] As a further technical solution of the present invention: the feeding mechanism includes a feeding hopper and a screw conveyor connected to the feeding hopper, the feeding hopper is installed above the side of the box body close to the water inlet pipe, the feeding hopper is inclined toward the direction close to the water inlet pipe, and a feeding port is opened on the screw conveyor.

[0024] As a further technical solution of the present invention: a vibrator is installed at the bottom of the feed hopper, the water inlet pipe, the first water outlet pipe and the second water outlet pipe are prism-shaped, the box is rectangular, and an antibacterial device is installed at the bottom of the separation cavity in the box.

[0025] As a further technical solution of the present invention, the shrimp shell separation device specifically comprises the following steps of: introducing water into the water inlet through a water pump, and the water flows into the separation chamber through the water inlet pipe, forming a horizontal water flow in a horizontal flow state in the separation chamber, and forming two water flows in the first cavity and the second cavity at the rear end of the box body respectively;

[0026] At this time, the shrimp powder is put into the feed port of the screw conveyor, and the shrimp powder falls into the separation chamber through the feed hopper. The vibration device on the feed hopper can make the shrimp powder fall into the separation equipment body more evenly;

[0027] After falling into the separation chamber, the shrimp meat will absorb water quickly, and the shrimp shell absorbs water more slowly, so the shrimp meat settles faster than the shrimp shell. The shrimp meat will settle quickly and be located in the lower half of the separation chamber, and the shrimp shell will be distributed in the upper half of the separation chamber. After moving a certain distance driven by the horizontal water flow, the shrimp meat and the shrimp shell will be completely separated in the vertical direction. The shrimp meat will enter the first outlet pipe from the first cavity at the bottom and flow out from the shrimp meat outlet, and the shrimp shell will enter the second outlet pipe from the second cavity above and flow out from the shrimp shell outlet. The equipment outlet is divided into two water streams. The solids in them can be separated to obtain the shrimp shell and shrimp meat components respectively. The separated water can be re-introduced into the water inlet through a pump for reuse.

[0028] In summary, the present invention includes at least one of the following beneficial technical effects:

[0029] The invention discloses a method for preparing krill protein, which comprises the following steps: firstly, pulverizing and screening shrimp powder to obtain particles with uniform particle size, then wetting the shrimp powder, utilizing the characteristic of shrimp meat absorbing water easily to increase the density difference between meat particles and shell particles, and finally separating the shell from the meat due to the difference in longitudinal sedimentation speed between the shell and the meat in a transverse water flow, thereby obtaining protein powder with low fluorine content and high protein content.

[0030] The method does not require a large amount of water to separate the protein from the shrimp shell through alkali dissolution and acid precipitation, thereby avoiding the generation of a large amount of salt-containing wastewater, high cost and environmental pollution; it also does not require the use of high-cost enzyme preparations and high-energy consumption processing processes to separate the protein from the shell, but instead fully utilizes the physical properties of the shrimp shell and shrimp meat, adopts a low-cost, natural, green and additive-free processing method, and realizes the production of protein. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a flow chart of the present invention.

[0032] Figure 2 It is a schematic diagram of the overall structure of the shrimp shell separation device of the present invention.

[0033] Figure 3 It is a side view of the shrimp shell separation device of the present invention.

[0034] Figure numerals: 1. Equipment body; 11. Water inlet pipe; 12. Box body; 121. Antibacterial device; 13. First water outlet pipe; 14. Second water outlet pipe; 2. Separation chamber; 3. Separation mechanism; 31. Sliding plate; 32. Lifting plate; 33. Connecting part; 34. Screw; 35. Support plate; 4. First chamber; 5. Second chamber; 6. Water inlet; 7. Shrimp meat outlet; 8. Shrimp shell outlet; 9. Feeding mechanism; 91. Feeding hopper; 911. Vibrator; 92. Screw conveyor; 93. Feeding port. DETAILED DESCRIPTION

[0035] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application; obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments, and all other embodiments obtained by ordinary technicians in this field based on the embodiments in the present application without making creative work are within the scope of protection of the present application.

[0036] In the description of the present application, it should be noted that the terms "upper", "lower", "inner", "outer", "top / bottom" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as limiting the present application. In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0037] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "provided with", "set / connected", "connected", etc. should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0038] Embodiment 1:

[0039] Reference Figure 1 , is a method for preparing krill protein disclosed in the present invention, comprising the following steps:

[0040] Step 1, crushing, crushing the defatted shrimp powder into a uniform particle size using a crusher, preferably 120-150 mesh, and the moisture content of the defatted powder is less than 10%;

[0041] Step 2: Screening: if the uniformity is not good, use a sieve to screen into different components such as 120-130 mesh, 130-140 mesh, 140-150 mesh, etc.; if the uniformity is good, proceed directly to the next step;

[0042] Step 3, mixing, mixing the graded shrimp powder with water in a certain mass ratio to achieve a wetting effect (shrimp meat particles absorb water quickly, while shrimp shells basically do not absorb water, thereby increasing the density difference between shrimp meat and shrimp shells), and the moisture content after mixing is ≥20%;

[0043] Step 4, shell-meat separation, adding wet shrimp powder evenly and slowly into the feed port 93 of the shrimp shell separation device, and separating the shrimp meat and shrimp shell through the shrimp shell separation device (adding wet shrimp powder evenly and slowly into the left end of the box, there is a water flow that flows slowly horizontally in the box; in the longitudinal direction of the box, the shrimp powder will slowly settle downward, because the shrimp meat particles and shrimp shell particles have been crushed and screened and graded in the early stage, so their sedimentation speed depends on their respective densities, and the shrimp meat settles faster while the shrimp shell settles slowly; in the transverse direction of the box, the shrimp powder will move forward with the water flow. In this way, from the perspective of the longitudinal section space in the box, the separation of shrimp meat and shrimp shell on the longitudinal section plane of the box can be achieved; the box can be used in combination with low temperature or blue light to inhibit the proliferation of microorganisms to control the number of microorganisms);

[0044] Step 5, solid-liquid separation, collecting shrimp powder at the outlet of the shrimp shell separation equipment and separating water, so as to obtain low-protein and high-fluoride shrimp shells (upper part) and high-protein and low-fluoride shrimp meat (lower part), and the separated water can be recycled;

[0045] Step 6: Drying and crushing: drying and crushing the shrimp meat to obtain edible krill protein.

[0046] In this embodiment, the moisture content of the defatted shrimp meal is 4.9-7.5%, the F content is 1700-1848 mg / kg, the protein content is 68.2-75.2%, and the crude fat content is 5.3-10.3%.

[0047] Reference Figure 2 In step 4, the shrimp shell separation device includes a device body 1, a separation chamber 2 for separating shrimp shells and shrimp meat is provided in the device body 1, a separation mechanism 3 is installed in the separation chamber 2, and the separation mechanism 3 separates the separation chamber 2 into a first chamber 4 and a second chamber 5 (see Figure 3 ), a water inlet 6 connected to the separation chamber 2 is provided at one end of the equipment body 1, and a shrimp meat outlet 7 and a shrimp shell outlet 8 are provided at the other end, the shrimp meat outlet 7 is connected to the first chamber 4, and the shrimp shell outlet 8 is connected to the second chamber 5, and a feeding mechanism 9 is arranged above the end of the equipment body 1 close to the water inlet 6.

[0048] The principle of this equipment is that the sedimentation speed of particles in water depends on their own density and particle size. Specifically, in this case, shrimp meat particles of the same particle size settle faster than shrimp shells. On this basis, the water flow is used to give a lateral displacement in the horizontal direction, thereby achieving the separation of shrimp shells and shrimp meat in the longitudinal space, and can be operated continuously. The efficiency of shrimp shell separation depends on the optimization of four factors: shrimp powder particle size, water flow speed, lateral displacement size, and water depth at the collection location.

[0049] The equipment body 1 includes a water inlet pipe 11, a box body 12, a first water outlet pipe 13 and a second water outlet pipe 14. The water inlet 6 is arranged at one end of the water inlet pipe 11, and the other end of the water inlet pipe 11 is connected to the box body 12. One end of the first water outlet pipe 13 and one end of the second water outlet pipe 14 are respectively connected to one end of the box body 12 away from the water inlet pipe 11; the first cavity 4 is connected to the interior of the first water outlet pipe 13, and the second cavity 5 is connected to the interior of the second water outlet pipe 14. The shrimp meat outlet 7 is arranged at one end of the first water outlet pipe 13, and the shrimp shell outlet 8 is arranged at one end of the second water outlet pipe 14.

[0050] The separation mechanism 3 includes a partition plate assembly and a lifting mechanism. The partition plate assembly is arranged between the first cavity 4 and the second cavity 5. The lifting mechanism is used to drive the partition plate assembly to move up and down in the separation cavity 2. The partition plate assembly includes a sliding plate 31, a lifting plate 32 and a connecting portion 33. One end of the connecting portion 33 is fixedly connected to the connection between the first water outlet pipe 13 and the second water outlet pipe 14, and the other end is connected to the lifting plate 32. A lifting mechanism is installed in the device body 1. The lifting mechanism is transmission-connected to the lifting plate 32. The lifting mechanism is used to drive the lifting plate 32 to move up and down in the separation cavity 2. In this embodiment, the connecting portion 33 is a soft rubber plate with elasticity. One end of the rubber plate is connected to the connection between the first water outlet pipe 13 and the second water outlet pipe 14, and the other end is connected to the lifting plate 32. The length of the soft rubber plate can enable the lifting plate 32 to move up and down.

[0051] The lifting mechanism includes a plurality of screws 34, which are symmetrically distributed on both sides of the separation chamber 2 and threadedly connected to the lifting plate 32. The plurality of screws 34 are driven by a motor to rotate simultaneously so that the lifting plate 32 moves up and down in the separation chamber 2. Two support plates 35 are integrally formed and fixedly connected to both sides of one end of the lifting plate 32 away from the connecting portion 33. The sliding plate 31 is overlapped on the top of the two support plates 35, and can not only move left and right, but also move up and down with the lifting plate 32.

[0052] In this embodiment, the lifting plate 32 can move up and down, so that the size of the materials can be separated according to the needs, the size of the first cavity 4 and the second cavity 5 can be adjusted, and the water depth of the collection position can be adjusted, which further improves the practicality. The sliding plate 31 can not only move up and down with the lifting plate 32, but also move left and right toward the water inlet 6, so that the separation path and separation time of the shrimp shell and the shrimp meat can be adjusted, which greatly improves the effect of shrimp meat separation.

[0053] The feeding mechanism 9 includes a feeding hopper 91 and a screw conveyor 92 connected to the feeding hopper 91. The feeding hopper 91 is installed above the side of the box 12 close to the water inlet pipe 11. The feeding hopper 91 is tilted toward the direction close to the water inlet pipe 11. A feeding port 93 is provided on the screw conveyor 92. A vibrator 911 is installed at the bottom of the feeding hopper 91. Among them, the feeding hopper 91 is not directly hard-connected with the equipment body 1, but a soft connection is adopted, and there is a vibrator 911 to ensure that the material can fall into the separation equipment body 1 more evenly. The water inlet pipe 11, the first water outlet pipe 13 and the second water outlet pipe 14 are in the shape of a prism, and the box body 12 is in the shape of a rectangular parallelepiped. In the present embodiment, one side of the equipment body 1 is a prism-shaped water inlet pipe 11, the purpose of which is to provide the equipment body 1 with a lateral water flow with controllable speed and in a horizontal flow state; next is the rectangular box body 12, which provides a space for the shrimp powder components to be dispersed; the separation mechanism 3 in the box body 12 can move left and right to adjust the lateral displacement, and can move up and down to adjust the water depth of the collection position, and on the longitudinal section, the separation mechanism 3 divides the box body 12 into two parts, upper and lower.

[0054] An antibacterial device 121 is installed at the bottom of the separation chamber 2 in the box 12. In this embodiment, the antibacterial device 121 can be a refrigeration device or a non-destructive antibacterial device 121 such as blue light. The purpose is to ensure that the microorganisms in the equipment do not proliferate, the shrimp powder does not rot, and the water therein can be reused. The outlet of the equipment is divided into two streams of water. The solids therein are separated to obtain the shrimp shell and shrimp meat components respectively. The separated water can be re-introduced into the water inlet 6 for reuse through a pump. Low temperature, blue light and other non-destructive and non-additive antibacterial technical means are used in the box to ensure the flavor of the product and that the microorganisms in the water used for return are not exceeded.

[0055] The shrimp shell separation device separates shrimp meat and shrimp shells, specifically including the following steps: water is introduced into the water inlet 6 through a water pump, and the water flows into the separation chamber 2 through the water inlet pipe 11, forming a horizontal water flow in a horizontal flow state in the separation chamber 2, and two water flows are formed in the first chamber 4 and the second chamber 5 at the tail end of the box body 12 respectively; at this time, shrimp powder is put into the feed port 93 of the screw conveyor 92, and the shrimp powder falls into the separation chamber 2 through the feed hopper 91, and the vibration device on the feed hopper 91 can make the shrimp powder fall into the separation equipment body 1 more evenly;

[0056] After falling into the separation chamber 2, the shrimp meat will settle quickly and be located at the underwater bottom of the separation chamber 2. The shrimp shell will be distributed in the upper part of the chamber due to its slow water absorption and slow sedimentation speed. In addition, with the continuous flow of water in the flow channel, after moving a certain distance in the horizontal direction, the shrimp meat and the shrimp shell will be completely separated in the vertical direction. The shrimp meat will enter the first water outlet pipe 13 from the lower first chamber 4 and flow out from the shrimp meat outlet 7. The shrimp shell will enter the second water outlet pipe 14 from the upper second chamber 5 and flow out from the shrimp shell outlet 8. The equipment outlet is divided into two water streams. The solids therein are separated to obtain the shrimp shell and shrimp meat components respectively. The separated water can be re-introduced into the water inlet 6 through a pump for reuse.

[0057] The following are examples of shrimp shell separation for shrimp powder of different purposes:

[0058] Embodiment 2:

[0059] The defatted powder has a moisture content of 5.1%, an F content of 1700 mg / kg, a protein content of 72.9%, and a crude fat content of 8.3%. The powder is crushed by a grinder to obtain shrimp meal of 140-150 mesh. The shrimp meal is mixed evenly with water in a ratio of 1:1 and slowly added into a box with a lateral water flow velocity of 0.25 m / s and a water temperature of 4°C. A horizontal baffle is set at a lateral distance of 12.5 m from the feeding point and a water depth of 0.5 m to divide the box into an upper and lower layer, and the shrimp meal in the water flow is collected respectively. The collected shrimp meal in the lower layer is dried to obtain krill protein with a moisture content of 4.6%, an F content of 40 mg / kg, and a protein content of 84.9%. Krill protein powder with low F content and high protein content is obtained.

[0060] Embodiment three:

[0061] The defatted powder has a moisture content of 5.1%, an F content of 1700 mg / kg, a protein content of 72.9%, and a crude fat content of 8.3%. The powder is crushed by a crusher to obtain shrimp powder with a mesh size of 80 to 100. The shrimp powder is mixed evenly with water at a ratio of 1:0.8, and the mixture is slowly added into a box with a lateral water flow velocity of 0.5 m / s and a water temperature of 25°C. A blue light antibacterial device is added into the box. A horizontal baffle is set at a lateral distance of 15 m from a feeding point and a water depth of 1 m to divide the box into an upper and lower layer, and the shrimp powder in the water flow is collected respectively. The collected shrimp powder in the lower layer is dried to obtain krill protein with a moisture content of 4.9%, an F content of 350 mg / kg, and a protein content of 80.5%, so as to obtain krill protein powder with a low F content and a high protein content.

[0062] Embodiment 4:

[0063] The defatted powder has a moisture content of 7.5%, an F content of 2471 mg / kg, a protein content of 68.2%, and a crude fat content of 10.3%. The defatted powder is crushed by a crusher to obtain shrimp powder with a mesh size of 100-120. The shrimp powder is mixed evenly with water in a ratio of 1:1.2, and the mixture is slowly added into a box with a lateral water flow velocity of 0.25 m / s and a water temperature of 2°C. A horizontal baffle is set at a lateral distance of 16 m from a feeding point and a water depth of 0.75 m to divide the box into an upper and lower layer, and the shrimp powder in the water flow is collected respectively. The collected shrimp powder in the lower layer is dried to obtain krill protein with a moisture content of 5.2%, an F content of 80 mg / kg, and a protein content of 80.9%, thereby obtaining krill protein powder with low F content and high protein content.

[0064] Embodiment five:

[0065] The defatted powder has a moisture content of 4.9%, an F content of 1848 mg / kg, a protein content of 75.2%, and a crude fat content of 5.3%. The powder is crushed by a crusher to obtain shrimp powder with a mesh size of 125 to 140. The shrimp powder is mixed with water in a ratio of 1:1 and evenly added into a box with a lateral water flow velocity of 0.35 m / s and a water temperature of 20°C. A blue light antibacterial device is added into the box. A horizontal baffle is set at a lateral distance of 17 m from a feeding point and a water depth of 0.5 m to divide the box into an upper and lower layer, and the shrimp powder in the water flow is collected respectively. The collected shrimp powder in the lower layer is dried to obtain krill protein with a moisture content of 5.1%, an F content of 30 mg / kg, and a protein content of 86.9%, so as to obtain krill protein powder with low F content and high protein content.

[0066] The implementation principle of the present invention is as follows: the present invention discloses a method for preparing krill protein, which comprises firstly crushing and screening shrimp powder to obtain particles with uniform particle size, then moistening the shrimp powder, utilizing the characteristic of shrimp meat absorbing water easily to increase the density difference between meat particles and shell particles, and finally separating the shell from the meat due to the difference in longitudinal sedimentation speed between the shell and the meat in the lateral water flow, thereby obtaining protein powder with low fluoride and high protein content.

[0067] The method does not require a large amount of water to separate the protein from the shrimp shell through alkali dissolution and acid precipitation, thereby avoiding the generation of a large amount of salt-containing wastewater, which is costly and pollutes the environment; nor does it require the use of high-cost enzyme preparations and high-energy consumption processing processes to separate the protein from the shell. Instead, the method makes full use of the physical properties of the shrimp shell and shrimp meat, adopts a low-cost, natural, green, and additive-free processing method, and realizes the production of protein.

[0068] The embodiments of this specific implementation method are all preferred embodiments of the present invention, and are not intended to limit the protection scope of the present invention. Therefore, all equivalent changes made based on the structure, shape, and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing krill protein, characterized in that: The following steps are involved: Step 1, crushing, crushing the defatted shrimp powder into a uniform particle size using a crusher, preferably 120-150 mesh, and the moisture content of the defatted powder is less than 10%; Step 2, screening, using a sieve to screen into different components of 120-130 mesh, 130-140 mesh, and 140-150 mesh; Step 3: Mixing: Mix the graded shrimp powder with water in a certain mass ratio to achieve a wetting effect. After mixing, the moisture content is ≥ 20%; Step 4, separating the shell from the meat, adding the wet shrimp powder evenly and slowly into the feed port of the shrimp shell separation device, and separating the shrimp meat from the shrimp shell through the shrimp shell separation device; Step 5, solid-liquid separation, collecting shrimp powder at the outlet of the shrimp shell separation device and separating water, so as to obtain low-protein and high-fluoride shrimp shells and high-protein and low-fluoride shrimp meat, and the separated water can be recycled; Step 6: Drying and crushing: drying and crushing the shrimp meat to obtain edible krill protein.

2. A method for preparing krill protein according to claim 1, characterized in that: In step 1, the defatted shrimp meal is a byproduct remaining after krill oil is extracted from full-fat shrimp meal, and the moisture content of the defatted shrimp meal is ≤10%, and the crude fat content is ≤11%.

3. The method for preparing krill protein according to claim 1, characterized in that: In step 4, the shrimp shell separation device comprises a device body (1), wherein a separation cavity (2) for separating shrimp shells from shrimp meat is provided in the device body (1), wherein a separation mechanism (3) is installed in the separation cavity (2), wherein the separation mechanism (3) separates the separation cavity (2) into a first cavity (4) and a second cavity (5), wherein a water inlet (6) communicating with the separation cavity (2) is provided at one end of the device body (1), and a shrimp meat outlet (7) and a shrimp shell outlet (8) are provided at the other end, wherein the shrimp meat outlet (7) is communicated with the first cavity (4), and the shrimp shell outlet (8) is communicated with the second cavity (5), and a feeding mechanism (9) is provided above one end of the device body (1) close to the water inlet (6).

4. A method for preparing krill protein according to claim 3, characterized in that: The device body (1) comprises a water inlet pipe (11), a housing (12), a first water outlet pipe (13) and a second water outlet pipe (14); the water inlet (6) is arranged at one end of the water inlet pipe (11); the other end of the water inlet pipe (11) is connected to the housing (12); one end of the first water outlet pipe (13) and one end of the second water outlet pipe (14) are respectively connected to one end of the housing (12) away from the water inlet pipe (11); The first cavity (4) is in communication with the interior of the first water outlet pipe (13), the second cavity (5) is in communication with the interior of the second water outlet pipe (14), the shrimp meat outlet (7) is arranged at one end of the first water outlet pipe (13), and the shrimp shell outlet (8) is arranged at one end of the second water outlet pipe (14).

5. A method for preparing krill protein according to claim 4, characterized in that: The separation mechanism (3) comprises a partition plate assembly and a lifting mechanism, wherein the partition plate assembly is arranged between the first cavity (4) and the second cavity (5), and the lifting mechanism is used to drive the partition plate assembly to move up and down in the separation cavity (2); The partition plate assembly comprises a sliding plate (31), a lifting plate (32) and a connecting portion (33); one end of the connecting portion (33) is fixedly connected to the connection between the first water outlet pipe (13) and the second water outlet pipe (14), and the other end is connected to the lifting plate (32); a lifting mechanism is installed in the equipment body (1); the lifting mechanism is transmission-connected to the lifting plate (32); and the lifting mechanism is used to drive the lifting plate (32) to move up and down in the separation chamber (2).

6. A method for preparing krill protein according to claim 5, characterized in that: The lifting mechanism comprises a plurality of screw rods (34), which are symmetrically distributed on both sides of the separation chamber (2) and are threadedly connected to the lifting plate (32). The plurality of screw rods (34) are driven by a motor to rotate simultaneously so that the lifting plate (32) moves up and down in the separation chamber (2).

7. A method for preparing krill protein according to claim 6, characterized in that: Two support plates (35) are integrally formed and fixedly connected to the two sides of one end of the lifting plate (32) away from the connecting portion (33), and the sliding plate (31) is overlapped above the two support plates (35) and can not only move left and right, but also move up and down following the lifting plate (32).

8. A method for preparing krill protein according to claim 7, characterized in that: The feeding mechanism (9) comprises a feeding hopper (91) and a screw conveyor (92) connected to the feeding hopper (91); the feeding hopper (91) is installed above the side of the box (12) close to the water inlet pipe (11); the feeding hopper (91) is inclined in a direction close to the water inlet pipe (11); and a feeding port (93) is provided on the screw conveyor (92).

9. A method for preparing krill protein according to claim 8, characterized in that: A vibrator (911) is installed at the bottom of the feed hopper (91), the water inlet pipe (11), the first water outlet pipe (13) and the second water outlet pipe (14) are in the shape of a prism, the box body (12) is in the shape of a rectangular parallelepiped, and an antibacterial device (121) is installed at the bottom of the separation chamber (2) in the box body (12).

10. A method for preparing krill protein according to claim 9, characterized in that: The shrimp shell separation device for separating shrimp meat from shrimp shells specifically comprises the following steps: introducing water into the water inlet (6) through a water pump, and the water flows into the separation chamber (2) through a water inlet pipe (11), forming a horizontal water flow in a horizontal flow state in the separation chamber (2), and forming two water flows in the first chamber (4) and the second chamber (5) at the rear end of the box body respectively; At this time, the shrimp powder is put into the feed port (93) of the screw conveyor (92), and the shrimp powder falls into the separation chamber (2) through the feed hopper (91). The vibration device on the feed hopper (91) can make the shrimp powder fall into the separation equipment body (1) more evenly. After falling into the separation chamber (2), the shrimp meat will absorb water quickly, while the shrimp shell absorbs water more slowly, so the shrimp meat settles faster than the shrimp shell. The shrimp meat will settle quickly and be located in the lower half of the separation chamber (2), while the shrimp shell will be distributed in the upper half of the separation chamber (2). After moving a certain distance driven by the horizontal water flow, the shrimp meat and the shrimp shell will be completely separated in the vertical direction. The shrimp meat will enter the first water outlet pipe (13) from the first chamber (4) at the bottom and flow out from the shrimp meat outlet (7), while the shrimp shell will enter the second water outlet pipe (14) from the second chamber (5) at the top and flow out from the shrimp shell outlet (8). The outlet of the equipment is divided into two water flows, and the solid matter therein is separated to obtain the shrimp shell and shrimp meat components respectively. The separated water can be reintroduced into the water inlet (6) through a pump for reuse.

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