JP2019083791A - Microbicidal cleaning method and microbicidal cleaning device of oyster shell - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and an apparatus for killing microorganisms of oyster shells, which can completely kill microorganisms contained in mud which has entered the complicated surface shape of the shell without weakening the oyster shells. SOLUTION: In the oyster shellfish killing microbial cleaning method, a step of generating pressurized microbial killing seawater by mixing and pressurizing seawater and a microbial killing agent, and a pressurized microbial killing seawater STW are aired. FIG. 1 includes a step of injecting the oyster shells arranged inside and a step of holding the oyster shell OS to which the microbial-killing seawater STW is attached in the air for a predetermined time [selection diagram].

Description

  The present invention relates to a method and apparatus for killing microorganisms attached to oyster shells by injecting pressurized seawater mixed with a microbicide to the oysters to wash the shells.

  The oyster shells are sometimes shipped as peeled oysters from which only the shell has been removed, and sometimes as shelled oysters with the shell attached. The shell of oyster shells has innumerable irregularities of complicated shape on the surface, and the narrow concave portion thereof has mud attached during aquaculture. In the case of a peeled oyster, the mud attached to the shell is washed using a rotary drum type washing apparatus (for example, Patent Document 1) which is washed by injecting water to the oyster shell put into the inside of the rotating drum. can do. On the other hand, in the case of a shelled oyster, it is difficult to use a rotary drum type cleaning device because the commercial value decreases when the shell is broken. Therefore, for example, the shelled oyster is washed manually by using an electric rotating brush, or washed by injecting seawater pressurized to about 3 MPa toward the oyster shell.

  However, since the oyster shell has a complicated surface shape, neither the brush nor pressurized seawater can reach the bottom of the recess, and it may not be possible to completely remove the attached mud. In oyster shells shipped from producers with mud remaining on the surface of the shell, the offensive odor of the product of microorganisms such as anaerobic bacteria contained in the mud may adversely affect the commercial value. If the pressure of pressurized seawater can be increased and sprayed to oysters, the detergency will be improved, but it is difficult to increase the pressure of seawater to such an extent that mud can be completely removed, since thin oyster shells are easily broken. .

  On the other hand, for the purpose of sterilizing food, for example, as described in Patent Document 2 or Patent Document 3, a method of washing food using a sodium hypochlorite solution has been proposed. Similarly to Patent Document 2 or Patent Document 3, although it is possible to wash oyster shells with a bactericidal agent such as sodium hypochlorite having high bactericidal effect, it is possible to use only such a bactericidal agent to wash oyster shells alone. However, it is difficult to completely kill bacteria contained in the mud because the bactericide does not reach the mud that has entered the intricately shaped recess. In addition, in the method of washing oyster shellfish in a highly bactericidal bactericidal agent, the shellfish may be opened and the germicide may enter inside, which may cause the shellfish to weaken or die.

  As a conventional technique, oyster shellfish may be sterilized prior to shipment by breeding the oyster shellfish in sterilized seawater in which sodium hypochlorite is mixed with seawater. In this method, although the effect of sterilizing and deodorizing the surface of the shell is recognized, there is a problem that the shellfish weakens due to the oyster shell hating chlorine and stopping breathing during breeding.

JP 2002-011421 A JP 2001-346509 A JP, 2010-246413, A

  The present invention provides a method and apparatus for the microbicidal cleaning of oyster shellfish which can completely kill the microorganisms contained in the mud in the complex surface shape of the shell without weakening the oyster shellfish. It will be an issue.

  In one aspect, the present invention provides an oyster sanitization method for killing attached microbes and washing oysters. The oyster shell bactericidal cleaning method comprises the steps of producing pressurized bactericidal seawater by mixing and pressurizing the seawater and the biocide, and the pressurized bactericidal seawater disposed in the air The process of injecting to oyster shellfish and the process of holding the oyster shellfish which the microbicidal seawater adhered to for a predetermined time in air are included.

  In one embodiment, the microbicide can comprise sodium hypochlorite. The concentration of sodium hypochlorite in the microbicidal seawater is preferably 3 ppm or more. In another embodiment, the microbicide can comprise electrolytic hypochlorous water. In yet another embodiment, the microbicide can also include both sodium hypochlorite and electrolytic hypochlorous acid. It is preferable that the predetermined time which hold | maintains the oyster shell to which microbicidal seawater adhered in the air is 3 minutes or more.

  In one aspect, the invention provides an oyster sanitizer that kills attached microbes and cleans oysters. The oyster shell bactericidal cleaning apparatus comprises a microbicide supply unit for supplying a microbicide, and a pressure unit for producing pressurized bactericidal seawater by mixing and pressurizing the seawater and the microbicide. It has an injection unit that jets pressurized microbicidal seawater toward the oyster shell held in the air, and a holding unit for holding, in the air, the oyster shell to which the microbicidal seawater adheres, for a predetermined period of time . In one embodiment, the biocide supply preferably comprises a metering pump for delivering a predetermined amount of biocide to the seawater.

  According to the present invention, it is possible to completely kill microorganisms such as anaerobic bacteria contained in the mud remaining in the shell of oyster shell without damaging the shell of oyster shellfish, so that the commercial value of the shelled oyster is improved. It is possible to wash the oyster shell without damaging it and to prevent the generation of offensive odor. Moreover, according to the present invention, even when odor is already attached to oyster shellfish, the odor can be effectively removed.

It is the schematic which shows the structure of the oyster shell microbe washing | cleaning apparatus by one Embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a schematic view showing a configuration of an oyster mussel microbe cleaning apparatus 10 (hereinafter referred to as an apparatus 10) according to an embodiment of the present invention. By using the apparatus 10, it is possible to wash away the mud adhering to the surface of the shell without damaging the shell of the oyster shell, and almost completely kill microbes such as anaerobic bacteria that live in the remaining mud It can be done.

  The apparatus 10 mixes and pressurizes the microbicide supply part which supplies the microbicide ST in order to mix it with seawater SW, and seawater SW and the microbicide ST, and the microbicidal seawater STW pressurized is mixed. And a pressure unit to generate. The pressurizing unit can include the pressurizing pump 11 and the motor 12 for driving the pressurizing pump 11. A power source P is connected to the motor 12, and the switch 19 is used to start and stop the motor 12. Seawater is supplied to the pressure pump 11 through the strainer 13 and the sea water hose 14. The pressure pump 11 is preferably a plunger pump capable of pressurizing seawater to an appropriate pressure necessary to achieve the object of the present invention, but is not limited thereto, and the shell of oyster shell OS is broken. Other reciprocating pumps and rotary pumps can also be used, as long as they can pressurize the seawater to a pressure that does not cause it and the deposited mud is effectively removed.

  The biocide supply may comprise a biocide tank 15, a metering pump 16, and a biocide hose 17. The microbicide tank 15 is a container for holding the microbicide ST, and its material, shape, capacity and the like can be appropriately selected as needed. A predetermined amount of the biocide ST held in the tank 15 is supplied to the seawater SW through the hose 17 by the metering pump 16. Preferably, the start and stop of the metering pump 16 is performed automatically by the signal from the switch 19.

  The microbicide supply unit may further include a microbicide injection unit 18 for supplying the microbicide ST to the seawater SW. In the apparatus 10, the microbicide injection unit 18 is provided on the water absorption side of the pressure pump 11.

  In this embodiment, the apparatus 10 passes the microbicide injection unit 18 before the seawater SW enters the pressure pump 11, where the biocide ST is supplied to the seawater SW, and the seawater SW and the biocide ST are supplied. Are configured to enter the pressure pump 11 together, but is not limited to this form. For example, the seawater SW and the microbicide ST may be separately fed directly to the pressure pump 11.

  The seawater SW and the microbicide ST that have entered the pressure pump 11 are mixed by the pressure pump 11 to become the microbicidal seawater STW, and are pressurized to a predetermined pressure. The predetermined pressure is set to such a pressure that the microbicidal seawater STW injected to the oyster shell OS by the injection unit described later does not damage the shell of the oyster shell OS and the attached mud is effectively removed. If it is, it will not be limited in particular, for example, it is preferred that it is about 3 MPa.

  As the microbicide ST, a substance capable of killing the microorganisms that live in the mud attached to the shell of the oyster shell OS is appropriately selected. When it is intended to produce no offensive product by killing the anaerobic bacteria contained in the mud attached to the shell of the oyster shell OS, the microbicide ST is a hypochlorite It is preferably an aqueous solution containing sodium acid. As the microbicide ST, it is also possible to use, for example, an aqueous solution of sodium chloride or an electrolytic solution obtained by electrolyzing hydrochloric acid.

  When sodium hypochlorite aqueous solution is used as the microbicide ST, the sodium hypochlorite concentration in the microbicidal seawater STW produced by mixing the seawater SW and the microbicide ST is 3 ppm or more It is preferably set, and more preferably set to 5 ppm or more. The concentration of sodium hypochlorite in the microbicidal seawater STW may be appropriately set according to the purpose. The sodium hypochlorite concentration of the microbicidal seawater STW can be made an appropriate value by appropriately adjusting the discharge amount of the microbicide ST by the metering pump 16. The discharge amount of the metering pump 16 can be adjusted, for example, based on the residual chlorine concentration contained in the waste water after oyster shell cleaning.

  The microbicidal seawater STW mixed and pressurized by the pressure pump 11 is discharged from the discharge port 11 a of the pressure pump 11. The discharge port 11a is connected to a hose 20 through which the pressurized microbicidal seawater STW passes, and the hose 20 is connected to the injection unit.

  The injection unit has an injection nozzle 21 for injecting pressurized microbicidal seawater STW toward the oyster shell OS. The jet nozzle 21 is, for example, a rotary nozzle whose jet port rotates and moves substantially parallel to the surface of the conveyor 22 so that the bactericidal seawater STW is jetted as uniformly as possible to the oyster shell OS arranged on the conveyor 22. It is preferable to use It is preferable that the injection | spray nozzle 21 is arrange | positioned above and below the conveyor 22, and the bactericidal seawater STW is simultaneously inject | poured to oyster shell OS from the upper and lower sides simultaneously. Such an injection nozzle 21 is also provided in a general up-and-down rotating nozzle-type oyster washer commercially available and will not be described in detail here. In addition, the injection | spray nozzle 21 is not limited to a rotary type nozzle, You may use one or more general purpose nozzles which can inject a liquid.

  When the microbicidal seawater STW is jetted to the oyster shell OS, the oyster shell OS is jetted on the conveyor 22 in a state of being exposed to air. Since oyster clams do not open their own shells in the air and have a high ability to hold seawater inside, if the bactericidal seawater STW is sprayed in the air, the bactericidal seawater STW will not enter the inside of the shells, and Is not weak.

  The oyster shell OS to which the microbicidal seawater STW has been attached is then held in the air for a predetermined time, for example, in a holding unit such as the stand 30. The oyster shell OS may be held as it is on the conveyor 22. In this case, the conveyor 22 functions as a holding unit. Furthermore, the oyster shell OS may be placed in a basket for transport and held, and in this case, the cage functions as a holding unit. While being held, the microbicidal seawater STW penetrates deep into the recess of the shell and the contained microbicide ST kills the microbe. Furthermore, the microbial agent ST can also remove the offensive odor already attached to the shell. The predetermined time for keeping in the air may be 3 minutes or more, as long as the microbicidal seawater STW containing the microbicide ST enters the back of the recess of the shell and kills the microbe. Preferably, it is 5 minutes or more.

  In the oyster shell OS held in the holding unit for a predetermined time, it is preferable that residual chlorine be washed using tap water or the like.

  The results of tests to verify the effectiveness of the microbicidal cleaning method according to the present invention are shown below. The present invention is not limited to the following tests and the results thereof.

  The test was conducted according to the following procedure. We prepared 1000 g of cultured oyster oysters that were fried from seawater and left with foreign substances such as mud, and divided them into two groups of 500 g each. One group of oyster shells (examples) was washed with bactericidal seawater according to the method according to the invention, and the other group of oysters (comparative examples) was washed with seawater which had not been specially treated. The microbicidal seawater used in the method according to the invention contained sodium hypochlorite at a concentration of 3 ppm. The oysters washed with microbicidal seawater were kept in air for 3 minutes. The oyster shells of each group were washed with aseptically treated 500 ml of pure water, and the number of general bacteria, the number of coliform bacteria, and the Vibrio parahaemolyticus number contained in the waste water after washing were determined. The number of general bacteria was analyzed by the standard agar plate culture method, and the number of E. coli bacteria and the most probable number of Vibrio parahaemolyticus were analyzed by the MPN calculation method. The test results are shown in Table 1.

  From the test results, the number of general bacteria and the number of coliforms contained in the washing drainage of the oyster shell group washed using the method according to the present invention is for the washing drainage of the oyster shell group washed with seawater that has not been specially treated. It can be seen that the number of bacteria contained was significantly reduced. In particular, in the case of the method according to the present invention, the facultative anaerobic bacteria E. coli count is almost undetected, thus having the effect of preventing the generation of malodor from the shell.

10 oyster shell kill apparatus 11 pressure pump (pressure section)
11a Discharge port (pressure part)
12 Motor (Pressure Unit)
13 strainer 14 seawater hose 15 biocide tank (biocide supply unit)
16 Metering pump (biocide supply part)
17 Biocide hose (biocide supply unit)
18 Microbicide injection unit (biocide supply unit)
19 switch 20 microbicidal seawater hose 21 rotary nozzle (injection part)
22 Conveyor 30 Holding stand (holding unit)
OS oyster shell P power ST microbicide STW microbicidal seawater SW seawater

Claims (9)

Producing pressurized microbicidal seawater by mixing and pressurizing the seawater and the microbicide;
Injecting pressurized microbicidal seawater into an oyster shell placed in the air;
And a step of holding the oyster shell to which the microbicidal seawater has been attached in air for a predetermined time, and killing the attached microorganism and cleaning the oyster shell, as well as the step of holding the oyster shell.   The method according to claim 1, wherein the microbicide comprises sodium hypochlorite or electrolytic hypochlorous acid.   3. The method according to claim 1, wherein the sodium hypochlorite concentration of the bactericidal seawater is 3 ppm or more.   The oyster shell microbe cleaning method according to any one of claims 1 to 3, wherein the predetermined time is 3 minutes or more. A microbicide supply unit for supplying a microbicide;
A pressure unit that generates pressurized microbicidal seawater by mixing and pressurizing seawater and a microbicide;
An injection unit for injecting pressurized microbicidal seawater toward the oyster shell held in the air;
An oyster clam microbe washing apparatus for killing oyster shellfish as well as cleaning the oyster shellfish, comprising: a holding unit for holding the oyster shellfish in which the microbicidal seawater has been adhered in air for a predetermined time.   6. The oyster shell bactericidal cleaning apparatus according to claim 5, wherein the microbicide comprises sodium hypochlorite or electrolytic hypochlorous acid.   The oyster shell sterilization cleaning apparatus according to claim 5 or 6, wherein the concentration of sodium hypochlorite in the microbicidal seawater is 3 ppm or more.   The oyster clam microbe cleaning apparatus according to any one of claims 5 to 7, wherein the predetermined time is 3 minutes or more. 9. The oyster shell bactericidal cleaning apparatus according to any one of claims 5 to 8, wherein the microbicide supplying unit has a metering pump for supplying a predetermined amount of the biocide to seawater.

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