Method and apparatus for producing feed and fertilizer for aquaculture

Abstract

To provide a method for producing a feed material, by which the feed material can be produced from an organism to be treated containing Clark's crayfish at a low cost without the fear of infection with Aphanomyces fungi, etc., and without destroying nutrients.SOLUTION: The method for producing the feed material includes a crushed material treatment for crushing a treatment object organism (S) containing at least Clark's crayfish to obtain a minced or slurry-like crushed material (F), an ultrasonic treatment for applying ultrasonic waves to the crushed material (F), and a non-heating sterilization treatment for sterilizing the crushed material subjected to the ultrasonic treatment without heating.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a method for producing a feed material, particularly suitable as a feed material for farmed fish, from a target organism including at least crayfish, and to a feed material and an apparatus for producing the feed material. [Background technology]

[0002] As marine resources continue to decline year by year due to factors such as overfishing and environmental changes, the importance of aquaculture, which can ensure a stable supply of marine products, has been increasing in recent years. For example, approximately 60% of the seafood currently sold in Japan is supplied by aquaculture. Aquaculture is carried out in a variety of ways, including traditional aquaculture, which uses natural water bodies to create fish pens, and so-called land-based aquaculture, which is carried out in artificially constructed aquaculture ponds. However, in recent years, the prices of fish meal (such as sardines) and krill, which are used as feed ingredients, have risen sharply due to a decline in fish catches, putting pressure on aquaculture businesses.

[0003] Meanwhile, there have been many reports of the proliferation of so-called invasive alien species, such as the American crayfish, in Japan's rivers, lakes, and other areas, threatening the habitat of endemic species. The Ministry of the Environment and the Ministry of Agriculture, Forestry and Fisheries have compiled a list of animals of foreign origin that are threatening the ecosystem, and have put forward measures such as submitting guidelines for preventing damage caused by invasive alien species. In addition to the American crayfish mentioned above, invasive alien species include largemouth bass, bluegill, red-eared slider turtle, bullfrog, black bass, silver carp, and giant pond snail. These species are captured and disposed of, which increases the cost of disposal. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 06-269250 Summary of the Invention [Problem to be solved by the invention]

[0005] As mentioned above, the aquaculture industry faces the problem of rising feed prices for fish meal (e.g., sardines) and krill (e.g., krill) due to declining catches. Therefore, using red crayfish, which are targeted for extermination and discarded as feed ingredients, could potentially solve the problem of rising feed prices in aquaculture. Furthermore, the production of feed for pig farming and other uses would broaden the range of applications. This would effectively utilize designated invasive species, which have traditionally been treated as waste. As described in Patent Document 1, there is an invention that extracts astaxanthin pigment oil from red crayfish and uses it to produce feed pellets for fish feed. Furthermore, as explained later in the "Embodiment of the Invention" section, red-eared sliders and red-eared sliders contain many components useful as feed, including taurine, vitamins, minerals, and protein. Taurine, vitamins, and other nutrients are sometimes added to feed, but with their prices rising, using red crayfish and other species as feed ingredients is desirable from both a nutritional and cost perspective.

[0006] However, when using crayfish, for example, as a feed ingredient, there are problems that need to be solved. Specifically, there is the risk of disease. Crayfish are highly likely to carry Aphanomyces, also known as crayfish plague, and if fish are infected by feeding them feed made from this, there is the possibility of causing severe damage. The method described in Patent Document 1 simply uses astaxanthin pigment oil extracted from crayfish using oils or organic solvents, so there is no problem with Aphanomyces. However, when producing feed using crayfish or other raw materials, measures against Aphanomyces are unavoidable.

[0007] Furthermore, American crayfish can also have the problem of parasites. Specifically, they can contain parasites belonging to the trematode genus Paragonimus. These parasites can be transmitted to humans and must be treated appropriately. They can also contain metacercaia and nematodes, which must be treated.

[0008] Therefore, it is possible to consider subjecting crayfish and other fish to high-temperature treatment for a specified period of time. This would likely kill Aphanomyces and other bacteria. However, high-temperature treatment is expensive and has the problem of denaturing proteins and destroying valuable nutrients. Furthermore, there are some fungi that do not die even at high temperatures. Other methods, such as high-pressure sterilization, gas displacement, and radiation, are also available, but they are all expensive.

[0009] The present invention aims to solve the above-mentioned problems by providing a method for producing feed materials from living organisms, including at least crayfish, at low cost without the risk of infection with Aphanomyces or the like and without destroying nutrients. [Means for solving the problem]

[0010] The invention described in claim 1 is a method for producing raw materials for feed from living organisms to be treated, including at least crayfish. Specifically, the method comprises a crushing process in which the living organisms to be treated are crushed to obtain a minced or slurry-like crushed material, an ultrasonic process in which ultrasonic waves are applied to the crushed material, and a non-thermal sterilization process in which the crushed material that has been subjected to ultrasonic treatment is sterilized without heating. In the invention described in claim 2, the non-thermal sterilization treatment is configured to perform electrolysis after adding hydrochloric acid or an electrolyte solution to the pulverized material. The invention described in claim 3 is a method for producing raw materials for feed, which is configured to include a dehydration treatment for dehydrating the pulverized material that has been subjected to non-heat sterilization treatment. [Effects of the Invention]

[0011] According to the present invention, target organisms, including crayfish, are crushed into a pulverized material and then subjected to ultrasonic waves, thereby separating Aphanomyces and other bacteria from the solid matter. The ultrasonically treated pulverized material is then subjected to non-thermal sterilization, thereby efficiently sterilizing the separated Aphanomyces and other bacteria. Because sterilization is performed without heating, nutrients contained in the target organisms, including crayfish, are not destroyed. In other words, an excellent feed ingredient can be produced. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a front view of an apparatus for producing raw materials for feed according to an embodiment of the present invention. FIG. [Figure 2] 1 is a flowchart showing a method for producing feed materials according to the present embodiment. [Figure 3] 1 is a graph showing the results of a taste test conducted on rainbow trout fed with feed produced from the feed ingredients according to the present embodiment and rainbow trout fed with feed produced from conventional fish meal. DETAILED DESCRIPTION OF THE INVENTION

[0013] <Organisms to be treated> This embodiment will be described. As shown in Figure 1, the feed material production apparatus 1 according to this embodiment is an apparatus for producing feed materials from crayfish and the like. In this specification, organisms to be treated that include at least crayfish are referred to as organisms to be treated S, S, .... The organisms to be treated S, S, ... may consist of only one species of crayfish, or may include not only crayfish but also other specified invasive species such as red-eared sliders, bullfrogs, largemouth bass, bluegills, black bass, silver carp, giant pond snails, and snapping turtles.

[0014] It has been found that red-eared sliders and crayfish have higher concentrations of certain nutrients than commercially available fish meal, which is used as a feed ingredient. For example, the taurine content per 100g of powder is 0.24% for commercial fish meal, while red-eared sliders and crayfish powders are 0.98%. Similarly, the crude fat content is 9.4% for commercial fish meal, while red-eared sliders and crayfish powders are 13.8%. Red-eared sliders have also been found to contain large amounts of vitamins B1 and B2. Therefore, it is preferable for the target organisms S, S, ... to contain a large amount of red-eared sliders and crayfish.

[0015] The organisms to be treated S, S, ... do not have to be limited to specific invasive species including crayfish. For example, they may include insects, annelids, etc. In any case, as long as they include crayfish, they will be treated as organisms to be treated S, S, ... by the feed raw material production apparatus 1 according to this embodiment.

[0016] <Feed raw material manufacturing equipment> As shown in Figure 1, the feed raw material manufacturing apparatus 1 of this embodiment is roughly composed of a crushing treatment device 3 that crushes the target organisms S, S, ... to produce crushed material F, a crushed material treatment tank 5 that sterilizes the crushed material F, and a dehydration device 7 that dehydrates the sterilized crushed material F.

[0017] <Crushing treatment device> The crushing device 3 is composed of a hopper 9 into which the organisms S, S, ... to be treated are fed, a crusher 10 that crushes the organisms S, S, ... to be treated that fall from the hopper 9, and a crushed material container 12 that receives the crushed material F. The crusher 10 can be of any type or structure as long as it is capable of crushing the organisms S, S, ... to be treated into minced or slurry-like crushed material F. The crusher 10 shown in FIG. 1 is composed of a pair of parallel rotating shafts 13, 13 and a plurality of crushing blades 14, 14, ... of a predetermined thickness that are provided on each of the pair of rotating shafts 13, 13. The plurality of crushing blades 14, 14, ... provided on one rotating shaft 13 and the plurality of crushing blades 14, 14, ... provided on the other rotating shaft 13 are arranged so that they alternately overlap. Therefore, when the rotating shafts 13, 13 rotate in the direction of the arrow, the organisms S, S, . . . to be treated are caught in the crushing blades 14, 14, .

[0018] In this embodiment, the pulverized material F pulverized by the pulverizer 10 is stored in the pulverized material container 12. However, for example, a belt conveyor or the like may be provided instead of the pulverized material container 12 to transport the pulverized material F to the pulverized material processing tank 5 described below. In this embodiment, the pulverizer 10 has been described as having only the pulverizing blades 14, 14, ... as pulverizing means, but a mixer or the like may be combined with other pulverizing means. A homogenizer, i.e., a fine agitator, for further fine pulverization may also be combined.

[0019] <Pulverized material processing tank> The pulverized material processing tank 5 is a tank into which the pulverized material F is placed and which efficiently sterilizes bacteria and mold contained in the pulverized material F without heating. The pulverized material processing tank 5 is provided with various devices for efficiently sterilizing the pulverized material F. Specifically, the pulverized material processing tank 5 is provided with an agitator 16, an ultrasonic processing device 17, and a non-thermal sterilization processing device 18. The agitator 16 may have any structure or type, but is designed to agitate the pulverized material F in the pulverized material processing tank 5.

[0020] <Ultrasonic treatment device> The ultrasonic treatment device 17 has an internal vibrator that vibrates the pulverized material treatment tank 5 at a frequency of 15 kHz or higher, preferably 40 kHz or higher, and more preferably around 500 kHz. This causes ultrasonic waves to act on the entire pulverized material F placed in the pulverized material treatment tank 5. Note that multiple ultrasonic treatment devices 17 may be provided depending on the size and shape of the pulverized material treatment tank 5. Furthermore, the ultrasonic treatment device 17 may be provided inside the pulverized material treatment tank 5. Bacteria such as pathogens adhere to the solid matter contained in large quantities in the pulverized material F, but the application of ultrasonic waves separates these bacteria from the solid matter. This allows for efficient sterilization using the non-thermal sterilization treatment device 18, which will be described next. Note that ultrasonic waves also have the effect of sterilizing some bacteria and eliminating parasites through the action of cavitation.

[0021] <Non-thermal sterilization treatment device> The non-thermal sterilization treatment device 18 is a device that adds or generates sterilizing water with sterilizing properties so that the pulverized material F can be sterilized without heating. For example, acidic water such as hydrochloric acid may be injected as the sterilizing water. This will sterilize bacteria separated from the solid material. When sterilizing with acidic water such as hydrochloric acid, a solution such as sodium hydroxide must be added after sterilization to neutralize the solution. Alternatively, a chlorine-based sterilizing agent solution such as sodium hypochlorite may be injected as the sterilizing water. While detoxification is not necessarily required when the concentration of such chlorine agents is low, when sterilizing using chlorine agents, it is generally necessary to detoxify the pulverized material F by injecting a harmless reducing agent such as sodium thiosulfate after sterilization. Alternatively, the pulverized material F can be electrolyzed to generate ozone. In this case, the sterilizing effect of ozone can be obtained.

[0022] Non-thermal sterilization treatment device 18 according to this embodiment is designed to produce sterilizing water and is configured as follows: That is, non-thermal sterilization treatment device 18 according to this embodiment is made up of solution addition device 20 and electrolysis device 21. Solution addition device 20 is a device that adds a solution containing ions to pulverized material F so that electrolysis device 21 can electrolyze pulverized material F, and adds, for example, hydrochloric acid, or an electrolyte solution such as saline.

[0023] The electrolysis device 21 is composed of a pair of electrodes, an anode 23 and a cathode 24, and a power supply 25 that supplies power to the pair of electrodes. When power is supplied, hypochlorous acid and hydrochloric acid are generated near the anode 23. The strong oxidizing power of hypochlorous acid in a weakly acidic environment efficiently kills bacteria in the pulverized material F. Operating the electrolysis device 21 while stirring with the agitator 16 can sterilize the entire pulverized material F. The hypochlorous acid generated by the electrolysis device 21 has high bactericidal power and is consumed relatively quickly. Therefore, detoxification with a reducing agent such as sodium thiosulfate is not particularly necessary. In the electrolysis device 21, the entire wall surface of the pulverized material treatment tank 5 can also be used as an electrode. In this case, only one of the anode 23 or cathode 24 needs to be placed in the pulverized material treatment tank 5. The electrodes also have the effect of sterilizing microorganisms by the direct action of an electric current when they come into contact with them. In either case, electrolysis is safe and environmentally friendly because it does not use chemicals.

[0024] <Dehydration treatment device> In this embodiment, the sterilized pulverized material F is sent to the dehydration device 7 via the valve 27 and dehydrated. The dehydration device 7 can be, for example, a filter press, but the type and structure of the device are not critical. The dehydrated solid material is used as a feed ingredient, while the liquid contains dissolved nutrients. For example, the liquid may be processed by so-called spray drying to produce a powder, which may then be mixed with the solid material to produce a feed ingredient. Alternatively, the sterilized pulverized material F may be directly processed by spray drying without being dehydrated by the dehydration device 7. Furthermore, the slurry-like pulverized material F can be used as a feed ingredient directly, or it can be solidified by adding a gelling agent, fiber, or plant-based feed such as wheat bran or soybean meal.

[0025] <Method for producing raw materials for feed according to the present embodiment> A method for producing raw materials for feed according to this embodiment will now be described. As shown in Figure 2, a crushing process S01 is carried out. That is, as shown in Figure 1, organisms to be treated S, S, ... are supplied to a hopper 9 of a crushing device 3, and a crusher 10 is operated. Then, the organisms to be treated S, S, ... that fall from the hopper 9 are crushed, and the crushed material F is stored in a crushed material container 12. When a predetermined amount has been accumulated, the crushed material F is placed in a crushed material processing tank 5.

[0026] Next, as shown in FIG. 2, ultrasonic treatment S02 is performed. That is, the ultrasonic treatment tank 5 is vibrated by the ultrasonic treatment device 17 to apply ultrasonic waves to the pulverized material F. As a result, as already explained, bacteria are separated from the solids contained in the pulverized material F. If parasites are present, the parasites are also separated. If the treatment is performed while the agitator 16 is running, ultrasonic waves can be applied evenly to the pulverized material F. Note that there may be cases where the fluidity of the pulverized material F is insufficient and ultrasonic waves cannot be applied sufficiently to the pulverized material F. In such cases, a solvent such as water may be added to the pulverized material F to ensure the necessary fluidity. At this time, vitamins, mineral-dissolved water, etc. may also be added to the water.

[0027] Next, as shown in FIG. 2, non-thermal sterilization treatment S03 is carried out. An electrolytic solution such as hydrochloric acid or saline solution is added using a solution adding device 20. Then, power is supplied from a power device 25 to the anode 23 and the cathode 24. Hypochlorous acid is generated to sterilize the pulverized material F. If this is carried out while the agitator 16 is running, the pulverized material F will be sterilized evenly. Note that ultrasonic treatment S02 may be carried out simultaneously with non-thermal sterilization treatment S03. Finally, as shown in FIG. 2, dehydration treatment S04 is carried out. Raw material for feed is obtained from the sterilized pulverized material F. [Example]

[0028] An experiment was conducted to confirm that crayfish can be appropriately sterilized when treated with the method for producing raw materials for feed according to the present embodiment. Experimental Method: Crayfish were crushed to obtain a slurry-like crushed product F, which was then divided into three containers, A1, X111, X12, and X13. Container A1 was subjected to 40 kHz ultrasound for 3 minutes, followed by the addition of saline solution, a pair of electrodes inserted, and power supplied for 3 minutes while stirring for sterilization. Container X11 was subjected to sterilization without ultrasound by adding saline solution, inserting a pair of electrodes, and power supplied for 3 minutes while stirring. Container X12 was subjected to ultrasonic treatment only, without sterilization. Container X13 was subjected to stirring only. The bacterial counts in the crushed product F in containers A1, X11, X12, and X13 were measured using the plate method (25 g of crushed product F was mixed with 225 cc of physiological saline, and the mixture was diluted 300-fold to form a test suspension, which was inoculated onto an agar medium and cultured at 37°C for 12 hours, and the number of colonies that appeared was counted using a colony counter). Test Results: The bacterial counts were as follows: no colonies were found in container A1, 16 colonies in container X11, 11 colonies in container X12, and 41 colonies in container X13. Consideration: It was confirmed that the number of bacteria was reduced to a certain extent by only the sterilization treatment performed by supplying electricity to the electrodes or by only the ultrasonic treatment. In other words, a certain degree of sterilization effect was confirmed. However, it was confirmed that the sterilization effect was further enhanced by using electrolysis and ultrasonic treatment in combination. In other words, it was confirmed that the method for producing raw materials for feed according to this embodiment has a high sterilization effect. [Example]

[0029] An experiment was conducted to confirm that parasites can be appropriately controlled when crayfish are treated using the method for producing raw materials for feed according to the present embodiment. Experimental Method: Crayfish infested with trematodes were selected and crushed to obtain a slurry-like crushed material F, which was then divided into five containers: A2, X21, X22, X23, and X24. Container A2 was sterilized by applying 40 kHz ultrasound for three minutes, followed by the addition of saline solution, the insertion of a pair of electrodes, and the application of electricity for three minutes while stirring. Container X21 was sterilized by adding saline solution, the insertion of a pair of electrodes, and the application of electricity for three minutes while stirring, without applying ultrasound. X22 was subjected to ultrasonic treatment only. Container X23 was added with a pesticide (aquatic benezal) and exposed for 24 hours. Container X24 was subjected to agitation only. 250 g of ground material F from each of containers A2, X21, X22, X23, and X24 was placed on the upper side of a mesh-separated beaker, water was added, and the mixture was stirred with a stirrer. The parasitic flukes that fell below the mesh, i.e., shed, were collected and counted under a dissecting microscope. Test Results: The measured number of parasites was 13 in container A2. Six parasites were confirmed to have fallen out in container X21, six in container X22, and 12 in container X23. No parasites were confirmed to have fallen out in container X24, with zero parasites. In order to check whether any detached parasites remained in the solid material, pulverized material F from container A2 was filtered and removed and examined under a microscope, but none were found. Consideration: It was confirmed that the number of surviving parasites was reduced to some extent even when the extermination treatment was carried out only by supplying electricity to the electrodes or by ultrasonic treatment alone. In other words, a certain degree of extermination effect was confirmed. However, it was confirmed that the extermination effect was further enhanced by combining electrolysis and ultrasonic treatment. In other words, it was confirmed that the method for producing raw materials for feed according to this embodiment has a high extermination effect against parasites. [Example]

[0030] Experiments were conducted to confirm that crayfish and red-eared sliders are excellent fish feed. Experimental Methods and Results: A feed material was produced by the feed material production method according to the present embodiment using only American crayfish and red-eared slider turtles as the organisms to be treated S. The obtained feed material was dried to produce powder B. Fish feed B1 was produced by mixing, by weight, powder B at 50%, vegetable oil cake at 15%, grains at 10%, sugars at 5%, and other ingredients at 20%. Feed Y was similarly produced using fish meal instead of powder B. That is, Feed Y was produced with a weight ratio of 50% fish meal, 15% vegetable oil cake, 10% grains, 5% sugars, and 20% other ingredients. Two aquaria, C and Z, were prepared, each containing five female rainbow trout approximately 550 mm in body length. The trout in aquaria C were fed diet B1, while the trout in aquaria Z were fed diet Y. The trout were fed three times a day for five days. A taste test was conducted on the rainbow trout raised in aquaria C and those raised in aquaria Z by 10 subjects. Evaluation was based on six criteria: flesh color (depth of pink), umami, firmness, fat content, aftertaste, and texture. The results are shown in Figure 3. The rainbow trout in aquaria Z were given a score of 1, and the trout in aquaria C were evaluated based on how many times that score they were. Redness was evaluated using a color chart index. Consideration: It was revealed that feeding rainbow trout with feed made from American crayfish and red-eared slider turtles resulted in high quality. It was confirmed that feed made from American crayfish and red-eared slider turtles is superior. [Explanation of symbols]

[0031] 1 Feed material manufacturing equipment 3 Crushing processing equipment 5 Crushed material treatment tank 7 Dehydration device 9 Hopper 10 Crusher 12 crushed material container 13 rotating shaft 14 Grinding blade 16 Agitator 17 Ultrasonic treatment device 18 Non-thermal sterilization treatment device 20 Solution addition device 21 Electrolysis device 23 Anode 24 Cathode 25 Power equipment S Organisms to be treated F. Crushed material

Claims

1. A crushing process in which a target organism including at least a crayfish is crushed to obtain a minced or slurry-like crushed product; ultrasonic treatment in which ultrasonic waves are applied to the pulverized material; a non-thermal sterilization treatment for sterilizing the pulverized material that has been subjected to the ultrasonic treatment without heating, thereby producing a raw material for feed.

2. 2. The method for producing raw materials for feed according to claim 1, wherein the non-thermal sterilization treatment is carried out by electrolyzing the pulverized material after adding hydrochloric acid or an electrolyte solution to the pulverized material.

3. 3. The method for producing a raw material for a feed according to claim 1, further comprising a dehydration treatment for dehydrating the pulverized material that has been subjected to the non-heat sterilization treatment.

4. A feed ingredient that is a raw material for feed, The feed material contains at least a living organism to be treated, including a crayfish; The organism to be treated is pulverized into a minced or slurry-like pulverized material, which is then subjected to ultrasonic treatment in which ultrasonic waves are applied to the pulverized material, and then subjected to non-thermal sterilization treatment in which the pulverized material is sterilized without heating.

5. 5. The feed material according to claim 4, wherein the non-thermal sterilization treatment is an electrolytic treatment after adding hydrochloric acid or an electrolyte solution to the pulverized material.

6. A crushing device for crushing a target organism including at least crayfish to obtain a minced or slurry-like crushed product; an ultrasonic treatment device that applies ultrasonic waves to the pulverized material; a non-thermal sterilization treatment device that sterilizes the pulverized material without heating, and

7. The feed material manufacturing apparatus includes a pulverized material treatment tank equipped with an agitator, 7. The feed raw material manufacturing apparatus according to claim 6, wherein the pulverized material processing tank is provided with the ultrasonic treatment device and the non-thermal sterilization treatment device, and the pulverized material pulverized by the pulverization treatment device is placed in the pulverized material processing tank, subjected to ultrasonic waves, and then subjected to non-thermal treatment.

8. The non-thermal sterilization treatment device is composed of a solution adding device that adds hydrochloric acid or an electrolyte solution to the pulverized material treatment tank, and an electrolysis device, 8. The feed material manufacturing apparatus according to claim 7, wherein the electrolysis device comprises a pair of electrodes consisting of an anode and a cathode placed in the pulverized material treatment tank, and a power device for supplying power to the electrodes.

9. The feed material production apparatus according to any one of claims 6 to 8, further comprising a dehydration device for dehydrating the pulverized material that has been subjected to non-thermal sterilization treatment.

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