JP6759399B2 - Sterilization method, sterilization system and storage method - Google Patents

Description

Embodiments of the present invention relate to sterilization methods, sterilization systems and storage methods.

In recent years, there has been increasing interest in safety for various food products. For example, fresh foods such as fruits and vegetables are no exception, and not only the growth process but also safety in each distribution process such as harvesting, collection or processing, packing, transportation, storage and sales to consumers. Countermeasures are desired.

One such measure is to prevent the growth or adhesion of bacteria in fresh foods and the like. It is expected that food safety will be guaranteed and damage to fresh foods will be prevented by appropriately cleaning or sterilizing fresh foods before they reach consumers.

However, depending on the type of fresh food, there are cases where the existing cleaning treatment or sterilization treatment is unsuitable. For example, some fruits and vegetables such as strawberries are not suitable for washing and sterilization using a liquid such as washing with water.

In addition, fresh food once packed is rarely sterilized before it reaches the consumer. For example, in the process of transportation and storage, which occupies a large weight in terms of time from shipment to delivery to consumers, at present, there are few means for suppressing the growth of bacteria such as fresh foods by methods other than cooling.

Japanese Unexamined Patent Publication No. 2013-99472 Japanese Unexamined Patent Publication No. 2003-339312

An object to be solved by the present invention is to provide a sterilization method, a sterilization system, and a storage method suitable for a distribution or storage process of an object that needs to prevent the growth or adhesion of bacteria.

The sterilization method according to one embodiment is a sterilization method in the distribution process of an object including fruits and vegetables or fresh flowers, which is shipped after being harvested at a growing place, transported by a transportation means, and stored or sold at the transportation destination. , Sterilization vaporized by a vaporizer when a plurality of breathable packing containers containing the above objects are stacked and arranged in a space surrounded by a wall in a state where the inside is communicated and transported or stored. the by Rukoto water is circulated in the space by the fan, the sterilization step of sterilizing the space, by the plurality of packaging containers with disposed on the space and said plurality of pressure reducing means facing the one of the packaging container By generating an air flow from the inside of the plurality of packing containers toward the inside of the space and depressurizing the inside of the plurality of packing containers, the vaporized sterilizing water in the space is discharged from each of the plurality of packing containers . Includes a depressurization step to spread inside.

FIG. 1 is a diagram showing an example of a process of production and distribution of fresh food. FIG. 2 is a diagram for schematically explaining the sterilization system and the sterilization method according to the first embodiment. FIG. 3 is a diagram schematically showing a configuration example of a first sterilization apparatus included in the sterilization system. FIG. 4 is a diagram schematically showing a configuration example of a second sterilizer included in the sterilization system. FIG. 5 is a flowchart showing an example of the sterilization process according to the first embodiment. FIG. 6 is a photograph of a medium in which bacteria were cultured in an experiment for verifying the bactericidal action of vaporized sterilizing water. FIG. 7 is a photograph of a medium in which bacteria were cultured in an experiment for verifying the bactericidal action of vaporized sterilizing water. FIG. 8 is a photograph of a medium in which bacteria were cultured in an experiment for verifying the bactericidal action of vaporized sterilizing water. FIG. 9 is a diagram schematically showing a configuration example of the first sterilizer according to the second embodiment. FIG. 10 is a diagram schematically showing a configuration example of a second sterilizer according to the second embodiment. FIG. 11 is a flowchart showing an example of the sterilization process according to the second embodiment. FIG. 12 is a diagram schematically showing a configuration example of the second sterilizer according to the third embodiment. FIG. 13 is a photograph of a medium in which bacteria were cultured in an experiment for verifying the bactericidal action when dehumidifying in addition to releasing vaporized sterilizing water. FIG. 14 is a diagram schematically showing a configuration example of the second sterilizer according to the fourth embodiment. FIG. 15 is a diagram schematically showing a configuration example of a vaporizer according to a fifth embodiment. FIG. 16 is a diagram showing an outline of differential pressure ventilation according to the sixth embodiment. FIG. 17 is a graph showing the results of an experiment on differential pressure ventilation. FIG. 18 is a graph showing an outline of an experiment of differential pressure ventilation for stacked packing containers. FIG. 19 is a graph showing the results of the experiment shown in FIG.

Some embodiments will be described with reference to the drawings. Throughout each embodiment, the same or similar elements are designated by the same reference numerals, and duplicate description will be omitted. Each figure is a schematic view for the purpose of contributing to the understanding of the embodiment, and the shapes and dimensions of the elements shown in each figure may differ from the actual ones, but these are disclosed and known as follows. It can be changed as appropriate by taking into consideration the technology.

In each embodiment, a sterilization system and a sterilization method for sterilizing a fresh food or a space around the fresh food in the distribution process of the fresh food are disclosed. Examples of fresh foods include fruits and vegetables such as fruits and vegetables, meats, and seafood. In this embodiment, fresh food is taken as an object as an example, but in addition to processed foods, raw materials / intermediate foods / additives for processed foods, decorative products such as fresh flowers, and medical / nursing fields are handled. The sterilization method, sterilization system, and storage method of each embodiment may be appropriately applied to the sterilization / transportation / storage method of all objects that need to prevent the growth or adhesion of bacteria, such as sanitary goods.

Here, as an example, the process of production and distribution of fruits and vegetables is shown in FIG. As shown in the flow of this figure, fruits and vegetables are grown outdoors or in indoor farmlands such as greenhouses and habitats such as plant plants, and are harvested when they grow appropriately. The harvested fruits and vegetables are collected at the collection site and subjected to various processing as necessary. In addition, fruits and vegetables are packed in predetermined units. The packing referred to here includes, for example, packing in a predetermined number or by a predetermined weight, and storage in a packing container such as a cardboard box or a dedicated packing case. After packing, the fruits and vegetables are shipped and transported to the sales destination by the carrier. As the mode of transportation, transportation by vehicle such as truck or train, transportation by ship, transportation by aircraft, etc. are assumed. In general, this transportation is carried out in a state where the packed fruits and vegetables are stored in a loading platform, a luggage compartment, a container, or the like. When the fruits and vegetables arrive at the sales destination, they are stored in a storage place as needed, displayed at a store or the like at an appropriate timing and sold to general consumers, or delivered to a restaurant or the like.

In each embodiment, it is assumed that the fresh food is a fruit or vegetable distributed in the distribution process as described above. However, it goes without saying that the same sterilization system and sterilization method can be applied to the distribution process of other kinds of fresh foods.

(First Embodiment)
FIG. 2 is a diagram for schematically explaining the sterilization system and the sterilization method according to the first embodiment. In the example of this figure, the sterilization system includes a first sterilizer 1 and a second sterilizer 2.

The first sterilization device 1 is arranged at the first sterilization place L1 such as a growing place or a collecting place of fruits and vegetables P, for example.
The first sterilization place L1 is different from the space in which the second sterilizer 2 described later is arranged, and may be a space completely open to the outside air, or the second sterilizer 2 described later is arranged. It may be a space similar to the space.

The first sterilizing device 1 sprays vaporized sterilizing water on the fruits and vegetables P after harvesting, collecting, or just before harvesting, and sterilizes the pests and the like adhering to the surface of the fruits and vegetables P without wetting the surface of the fruits and vegetables P. Perform the first sterilization step. As the sterilizing water used by the first sterilizing device 1, for example, hypochlorite water such as electrolyzed water can be used.

Electrolyzed water is water mixed with substances obtained by electrolyzing water to be electrolyzed to which an electrolyte such as potassium chloride or sodium chloride is added. Alkaline ionized water (alkaline electrolyzed water) showing alkalinity is produced from the cathode side. Acidic electrolyzed water containing hypochlorous acid is produced from the anode side of the electrode.

The fruits and vegetables P that have undergone the first sterilization step after being harvested, or the fruits and vegetables P that have been harvested after undergoing the first sterilization step, are packed (accommodated) in the packing container 3 at, for example, a collection place or a processing place. As the packing container 3, for example, a box made of corrugated cardboard, foamed styrol, or the like, a special packing case, or the like can be used. The fruits and vegetables P are shipped in a state of being contained in the packing container 3, and are transported by a transportation means L2 such as a vehicle, a ship, or an aircraft. The packing container 3 has a portion open to the outside, and the air around the fruits and vegetables P and the air inside the packing container 3 can be circulated.

The purpose of the first sterilization step is to sterilize the surface of fruits and vegetables P, and if the purpose can be achieved by carrying out after packing, the order of packing and the first sterilization step does not matter. Moreover, the packing form does not matter.

The second sterilizer 2 is arranged, for example, in the loading platform or luggage compartment of the transportation means L2. The place where the second sterilizer 2 is arranged here is the space 5 surrounded by the wall portion 4. A packing container 3 containing fruits and vegetables P is also arranged in this space 5. The wall portion 4 may be a wall surface of a loading platform or a luggage compartment, or may be a wall surface of a container placed on the loading platform or the luggage compartment. Such a wall portion 4 surrounds the space 5 above, below, and on all sides, and has the same degree of airtightness as a normal luggage compartment or container.

As a space 5 having a certain degree of airtightness, a container used for transporting a vehicle, a ship, an aircraft, etc., a luggage compartment thereof, a refrigerator / freezer that can be stored at a low temperature, a food storage for storing food, etc.・ There is a warehouse. Even if the airtightness is completely ensured or the airtightness is open to some extent, there is no problem as long as the effect of the present embodiment is obtained.

The second sterilizer 2 releases vaporized sterilizing water into the space 5 to remove bacteria (floating bacteria) floating in the space 5 and bacteria (surface bacteria) adhering to the surface of the wall 4 or the packing container 3. Perform a second sterilization step to sterilize. When the airtightness of the packing container 3 is low, the inside of the packing container 3 can also be sterilized in the second sterilization step. If the second sterilization step can also serve as the first sterilization step for sterilizing the surface of fruits and vegetables P, the first sterilization step can be omitted.

The sterilization by the second sterilizer 2 is performed, for example, until the transportation means L2 arrives at the transportation destination. As the vaporized sterilizing water used by the second sterilizing device 2, for example, electrolyzed water similar to that of the first sterilizing device 1 can be used.

Such a first sterilization step and a second sterilization step do not wet the surface of the fruit and vegetable P, the packing container 3, and the like.
Further, since both the first sterilization step and the second sterilization step sterilize the surface of the fruits and vegetables P or the space where the fruits and vegetables P are arranged with the vaporized sterilizing water, the surface of the fruits and vegetables P or the packing container 3 is not damaged.

Further, even when the fruits and vegetables P are stored in the packing container 3, if vaporized sterilizing water enters the inside of the packing container 3 through holes or gaps provided in the packing container 3, the first sterilization step and the second sterilization step are performed. The surface of fruits and vegetables P can be sterilized in.

In the present specification, the release of vaporized sterilizing water or the like by the first sterilizing device 1 is mainly referred to as spraying, and the release of vaporized sterilizing water or the like by the second sterilizing device 2 is mainly referred to as release. The terms spraying and releasing can all include vaporized sterilized water or an action of releasing the sterilized water and mist, and may refer to the same action.

Subsequently, an example of the configuration applicable to the first sterilizer 1 and the second sterilizer 2 will be described. FIG. 3 is a diagram schematically showing a configuration example of the first sterilizer 1. The first sterilizer 1 shown in this figure includes a tank 10, a pipe 11, a pump 12, a spray device 13, and a controller 14.

The tank 10 stores hypochlorite water, which is an example of sterilizing water. The hypochlorous acid water is appropriately replenished manually through a water supply port provided in the tank 10 or by a power source such as a pump via a water supply pipe connected to the tank 10.

One end of the pipe 11 is connected to, for example, the bottom surface of the tank 10, and the other end is connected to the spray device 13. The pump 12 functions as a liquid feeding device that supplies the hypochlorous acid water in the tank 10 to the spraying device 13, and is provided in the pipe 11. The pump 12 can adjust the flow rate of the hypochlorous acid water sent to the spray device 13 by, for example, variable control of the rotation speed. The hypochlorous acid water may be sent from the tank 10 to the spraying device 13 by using the head pressure or the like. In this case, for example, by providing the piping 11 with a solenoid valve having a variable opening degree, the flow rate of the hypochlorous acid water sent to the spray device 13 can be adjusted.

The spraying device 13 includes a housing 15 having an intake port 15a and an exhaust port 15b, and a vaporizer 16 and a fan 17 housed in the housing 15. In the example of FIG. 3, the pipe 11 extends inside the housing 15 and is connected to the vaporizer 16.

The vaporizer 16 vaporizes the hypochlorous acid water supplied through the pipe 11 and releases the bactericidal component into the space. At the same time, the vaporizer 16 also generates mist having a relatively small particle size. In the first sterilization step, for example, an ultrasonic method can be adopted as a method of vaporization that does not mainly aim to generate such mist. In this case, the vaporizer 16 vibrates the container for storing the hypochlorous acid water supplied through the pipe 11 and the hypochlorous acid water stored in the container by ultrasonic waves, and the hypochlorous acid water is vibrated from the liquid level. It has an ultrasonic oscillator that generates a mist of chlorinated water. In addition, as a method of vaporizing hypochlorous acid water by the vaporizer 16, a method of vaporizing (atomizing) hypochlorous acid water by discharging hypochlorous acid water from a nozzle having micropores, etc. May be adopted. Furthermore, there is a natural vaporization formula in which the vaporization filter is blown by a fan or the like. However, since the purpose is to sterilize the object without getting it wet, it is desirable that the amount of mist generated is small and the particle size is small. In addition, the vaporizer including the vaporizer of the second sterilizer described later may be any vaporizer as long as it has a vaporization method by heat such as a thermal method and other vaporizing functions, as well as the equivalent of the above-mentioned method.

The fan 17 sends the vaporized hypochlorite water and mist generated by the vaporizer 16 to the outside of the housing 15. Specifically, air is taken into the housing 15 from the intake port 15a as the fan 17 rotates, and this air is discharged from the exhaust port 15b together with the vaporized hypochlorite water and mist generated by the vaporizer 16. (Spray). By variable control of the rotation speed of the fan 17, it is possible to adjust the amount and air volume of vaporized hypochlorous acid water and the like sprayed on the outside of the housing 15.

The controller 14 includes, for example, a processor that plays a central role in controlling the first sterilizer 1, a memory that stores various setting conditions and computer programs executed by the processor, and a power supply device that generates a voltage to be supplied to each unit. There is. The controller 14 controls a pump 12, a vaporizer 16, a fan 17, and the like. In the example of FIG. 3, the controller 14 is connected to an input / output device 18 including a display device such as an indicator light or a display, an input device such as a button or a switch, and an audio output device such as a speaker.
For example, the controller 14 controls the rotation speed of the fan 17 so as not to wet the surface of fruits and vegetables P such as strawberries, cherries, and okra.

Such vaporized sterilizing water (hypochlorite water) can be sterilized without wetting the surface of fruits and vegetables P, and even if mist with a small particle size that is generated at the same time adheres, it evaporates quickly, so fruits and vegetables The surface of P and the like are not excessively wetted. Therefore, it is suitable for sterilizing fruits and vegetables P that are not suitable for washing with water, such as strawberries, cherries, and okra. The particle size of the mist (liquid mist) that does not wet the surface of the fruit and vegetable P is, for example, about 50 μm or less.

As described above, the first sterilization step (or the spraying step described later) includes spraying the liquid particles obtained by mistizing the sterilizing water, and the particle size of the liquid particles is the size of the fruits and vegetables when the liquid particles adhere to the fruits and vegetables P. It does not wet P.

Further, the radish, burdock, etc. may not be the vaporized sterilizing water described above, but the sterilizing water may be poured as the first sterilizing step. In the present application, even when the water is flushed in this way, it is treated as a kind of spray of sterilizing water. Further, the spray may be sprayed by discharging sterilizing water from a nozzle having micropores.

FIG. 4 is a diagram schematically showing a configuration example of the second sterilizer 2. The second sterilizer 2 shown in this figure includes a tank 20, a pipe 21, a pump 22, a vaporizer 23, and a controller 24.

The tank 20 stores hypochlorite water, which is an example of sterilizing water. The hypochlorous acid water is appropriately replenished manually through a water supply port provided in the tank 20 or by a power source such as a pump via a water supply pipe connected to the tank 20.

One end of the pipe 21 is connected to, for example, the bottom surface of the tank 20, and the other end is connected to the vaporizer 23. The pump 22 functions as a liquid feeding device that supplies the hypochlorous acid water in the tank 20 to the vaporizer 23, and is provided in the pipe 21. The pump 22 can adjust the flow rate of the hypochlorous acid water sent to the vaporizer 23, for example, by variable control of the rotation speed. The hypochlorous acid water may be sent from the tank 20 to the vaporizer 23 by using the head pressure or the like. In this case, for example, by providing the piping 21 with a solenoid valve having a variable opening degree, the flow rate of the hypochlorous acid water sent to the vaporizer 23 can be adjusted.

The vaporizer 23 includes a housing 25 having an intake port 25a and an exhaust port 25b, and a vaporizer 26 (vaporizing member) and a fan 27 housed in the housing 25. In the example of FIG. 4, the pipe 21 is connected to the upper wall of the housing 25, and hypochlorous acid water is dropped onto the vaporizer 26.

As the vaporizer 26, for example, a water absorption filter that absorbs hypochlorous acid water dropped from the pipe 21 can be used. This water absorption filter may have a fine structure such as a fine honeycomb structure in order to increase the contact area with air and efficiently vaporize the hypochlorous acid water. Further, the water absorption filter is made of a material that does not easily react with hypochlorous acid water, for example, a polyolefin-based material such as polyethylene or polypropylene, or an inorganic material, or the surface is coated with these materials. There may be. By using such a water absorption filter, it is possible to prevent corrosion of the water absorption filter by hypochlorous acid water and deactivation of hypochlorite water. The vaporizer 26 vaporizes the hypochlorous acid water, and at the same time, mist having a relatively small particle size may be generated.

The fan 27 discharges the gas vaporized by the vaporizer 26 to the outside of the housing 25. Specifically, air is taken into the housing 25 from the intake port 25a as the fan 27 rotates, and this air is discharged (released) from the exhaust port 25b together with the gas vaporized by the vaporizer 26. By variable control of the rotation speed of the fan 27, the amount of gas released to the outside of the housing 25 can be adjusted.

The controller 24 includes, for example, a processor that plays a central role in controlling the second sterilizer 2, a memory that stores various setting conditions and computer programs executed by the processor, and a power supply device that generates a voltage to be supplied to each unit. .. The controller 24 controls the pump 22, the vaporizer 26, the fan 27, and the like. In the example of FIG. 4, the controller 24 is connected to an input / output device 28 including a display device such as an indicator light or a display, an input device such as a button or a switch, and an audio output device such as a speaker.

The flow of the sterilization process using the first sterilizer 1 and the second sterilizer 2 will be described with reference to the flowchart of FIG.
The worker at the first sterilization place L1 where the first sterilization device 1 is located inputs an operation start instruction by, for example, operating the input / output device 18 in order to sterilize the surface of the fruits and vegetables P (step S11). In response to the input of this instruction, the controller 14 starts spraying the hypochlorous acid water (step S12). That is, the controller 14 starts the operation of the pump 12, the carburetor 16, and the fan 17. As a result, the hypochlorite water in the tank 10 is vaporized by the vaporizer 16 to become vaporized sterilized water containing, for example, mist, which is sprayed from the exhaust port 15b. The fruits and vegetables P are arranged at a place exposed to the vaporized sterilizing water, for example, at a position facing the exhaust port 15b, and the surface thereof is sterilized by the vaporized sterilizing water.

While spraying the vaporized sterilizing water, the controller 14 waits for the timing of the end of the process (step S13). The processing end timing can be, for example, a timing at which an instruction to end the processing is input by operating the input / output device 18, a timing at which a certain time has elapsed from the start of spraying, or the like. When the timing of the end of the process has arrived (YES in step S13), the controller 14 stops spraying the vaporized sterilizing water.

After the above first sterilization step (steps S11 to S13), the fruits and vegetables P are housed in the packing container 3 and transported. At the time of this transportation, the operator inputs an operation start instruction by, for example, operating the input / output device 28 of the second sterilizing device 2 in order to sterilize the space 5 in which the packing container 3 is arranged (step S14). In response to the input of this instruction, the controller 24 starts to release the vaporized sterilizing water and mist (step S15). That is, the controller 24 starts the operation of the pump 22 and the fan 27. As a result, the hypochlorous acid water in the tank 20 is vaporized by the vaporizer 26, and the vaporized gas is discharged from the exhaust port 25b. The released gas (vaporized substance) disperses in the space 5 and sterilizes the bacteria floating in the space 5. Further, the released gas (vaporized substance) reaches the surface of a wall portion 4 (ceiling, wall, floor, etc.) in the space 5 or an object such as a packing container 3 arranged in the space 5, and these walls. Kills bacteria present on the floor, or the surface of an object. In the vaporizer 23, bacteria contained in the air taken in from the space 5 come into contact with the vaporizer 26 and are sterilized by the hypochlorous acid water absorbed by the vaporizer 26.

While the sterilized water is vaporized and discharged, the controller 24 waits for the timing of the end of the process (step S16). The timing of processing end is, for example, the timing when the transportation means L2 arrives at the transportation destination. Specifically, when the packing container 3 is unloaded from the transportation means L2, the operator operates the input / output device 28 to end the processing. It can be the timing to input the instruction. In addition, the timing of the end of the treatment can be the timing when a certain time has elapsed from the start of vaporization and release. In response to the timing of the end of the process (YES in step S16), the controller 24 stops the vaporization and release of the sterilizing water.

This completes the sterilization process shown in the flowchart. By using a sterilization treatment including such a first sterilization step (steps S11 to S13) and a second sterilization step (steps S14 to S16), the surface of fruits and vegetables P and its packaging can be suitably sterilized, and the final consumer or the like It can be provided in a safe and fresh condition.

Further, by spraying the sterilized water vaporized in the first sterilization step, the surface of the fruits and vegetables P does not get wet, and the surface of the fruits and vegetables P unsuitable for washing with water can also be sterilized. Further, in the second sterilization step, since the sterilization is performed with the vaporized sterilizing water, the packing container 3 and the like are not wetted.

Further, since the mist released together with the sterilizing water vaporized in the space 5 in the second sterilization step contains water vapor, the humidity of the space 5 is increased. As a result, the humidity suitable for maintaining the freshness of the fruits and vegetables P is realized, the drying of the fruits and vegetables P contained in the packing container 3 is prevented, and the freshness of the fruits and vegetables P is maintained.
As described above, the sterilization treatment according to the present embodiment is suitable for the distribution process of fresh foods such as fruits and vegetables P.

Here, the time for spraying the vaporized sterilizing water in the first sterilization step is T1, and the time for vaporizing and releasing the hypochlorite water in the second sterilization step is T2. Since the first sterilization step is performed before the fruit and vegetable P is shipped and the second sterilization step is performed during transportation, T1 <T2 in many cases.

In the first sterilization step, since it is necessary to sterilize the surface of fruits and vegetables P well in a short time, it is preferable to use hypochlorite water having a relatively high effective chlorine concentration. On the other hand, in the second sterilization step, hypochlorous acid water having a relatively low effective chlorine concentration can be used in order to sterilize the space 5 for a long time during transportation. For example, if the effective chlorine concentration of the hypochlorite water used in the first sterilization step is D1 and the effective chlorine concentration of the hypochlorite water used in the second sterilization step is D2, the relationship of D1> D2 is established. It can be established. For example, D1 can be about twice or more that of D2.

The effective chlorine concentration in the mist sprayed by the first sterilizer 1 is about 1/2 to 1/3 lower than the concentration of the hypochlorite water in the tank 10. Therefore, the effective chlorine concentration of the hypochlorous acid water stored in the tank 10 may be at least twice or three times or more the effective chlorine concentration of the target mist. For example, if the effective chlorine concentration that can be added to food is 80 ppm or less, the effective chlorine concentration of the sprayed hypochlorite water is 80 ppm or less, and the effective chlorine concentration of the hypochlorite water stored in the tank 10 is 80. It may be ~ 160 ppm.

Further, in the second sterilization step, the amount of hypochlorite water consumed by the second sterilizer 2 may be relatively small so that the hypochlorite water in the tank 20 is not deficient during long-term transportation. .. For example, the amount of hypochlorous acid water consumed per unit time by the second sterilizer 2 is smaller than the amount of hypochlorous acid water consumed per unit time by the first sterilizer 1. Is expected. The consumption of hypochlorous acid water can be adjusted by changing the operating conditions of the pump 12 and fan 17 of the first sterilizer 1 and the pump 22 and fan 27 of the second sterilizer 2. As an example, if the air flow rate (volume flow rate) of the fan 17 is Q1 and the air flow rate (volume flow rate) of the fan 27 is Q2, the relationship of Q1> Q2 can be established. For example, Q1 can be about twice or more that of Q2.

Further, in the first sterilization step, it is better to arrange the object so that the air blown from the fan 17 directly hits the surface of the object, and in the second sterilization step, the air blown from the fan 27 is the entire space 5. It is advisable to once blow air toward the ceiling so that the air circulates indirectly so that the air hits the object indirectly.

That is, the second sterilization step may include a circulation step in which the vaporized substance in which the sterilizing water (electrolyzed water, hypochlorite water) is vaporized is circulated in the space 5. Further, in this one embodiment, the fan 27 functions as a circulation means for circulating the vaporized electrolyzed water in the space 5. The circulation means is not only the means for forcibly circulating the fan 27, but also the diffusion of sterilized water (electrolyzed water, hypochlorous acid water) vaporized substances by convection in the space 5, Brownian motion, etc., and their equivalents. Anything other than that having a function of circulating the vaporized substance in the space 5 may be used. The vaporized substance contains a gas obtained by vaporizing sterilized water. Further, in this circulation step, the floating bacteria that float in the space 5 come into contact with the vaporizing member such as the vaporizer 26 to sterilize the floating bacteria, and the vaporized substance is dispersed in the space 5, so that the space 5 By sterilizing the airborne bacteria inside, the vaporized substance reaches the surface of an object such as a wall, a floor, or a packing container 3 arranged in the space 5, and the surface of the wall, floor, or the object is reached. Includes killing surface bacteria present in.

The sterilization by the first sterilization step is to sterilize the bacteria mainly adhering to the surface of the freshly harvested product and the object stored in a space open to the outside air, so that a large amount of hypochlorite Although it is necessary to supply water, sterilization by the second sterilization step is less than that of the first sterilization step because it mainly sterilizes bacteria floating in a closed space after the surface of the object is sterilized. It is sufficient to supply hypochlorite water. Instead, it is necessary to supply hypochlorous acid water for a long period of time over the entire storage period and transportation period.

The humidity in the space 5 of the second sterilization step may be 50 to 100%, preferably 90 to 100% from the viewpoint of preserving the object such as fruits and vegetables P. In container transportation by train or truck, the indoor temperature fluctuates greatly depending on the season, and the amount of hypochlorous acid water saturated in the space 5 also fluctuates due to this temperature fluctuation. Therefore, this fluctuation may be predicted in advance and the humidity may be set to 50 to 90%.

The inventors have experimentally verified the bactericidal action of the vaporized sterilizing water used in the first sterilization step. In this experiment, after spraying over a predetermined period of time the hypochlorite water vaporized into the booth with placing the harvested okra into approximately 1 m ³ of booth humidity 50-90%, okra Bacteria were collected from the surface, and the collected bacteria were cultured in a medium in an environment of 37 ° C. for about 1 day. For comparison, okra was immersed in hypochlorite water for about 2 minutes, bacteria were collected from the surface of the okra after the immersion, and the collected bacteria were cultured in the same manner.

FIG. 6 is a photograph in which the above experiment was carried out four times (N1 to N4) and the medium in which the bacterium was cultured was photographed. The hypochlorite water stored in the tank 10 used here has a pH of 6 and an effective chlorine concentration of 76 ppm. In each photograph, the medium is arranged in a circular petri dish, and the whitish part corresponds to the cultured bacteria. When immersed in hypochlorous acid water (“electrolyzed water immersion” in the figure) and when vaporized hypochlorite water is sprayed for 1 hour (“vaporized electrolyzed water 1 hour spray” in the figure) In all of N1 to N4, the amount of the cultured bacteria was smaller when immersed in hypochlorite water. On the other hand, when the vaporized hypochlorous acid water was sprayed for 24 hours (“vaporized electrolyzed water sprayed for 24 hours” in the figure), the amount of cultured bacteria was larger than that in the case of spraying for 1 hour. It was significantly less, and the same or better results as in the case of immersion were obtained.

In FIG. 7, the concentration of hypochlorous acid water stored in the tank 10 was 152 ppm, the concentration was doubled from the verification of FIG. 6, and the spraying time was made finer, and the above experiment was performed four times (N1 to N1). It is a photograph which carried out over N4) and photographed the culture medium in which the bacterium was cultured. The spraying time is 1 hour (“1 hour spray of vaporized electrolyzed water” in the figure), 3 hours (“3 hour spray of vaporized electrolyzed water” in the figure), 6 hours (“6 hours spray of vaporized electrolyzed water” in the figure). ) And 24 hours (“Vaporized electrolyzed water 24 hours spray” in the figure). From FIG. 7, it can be seen that the longer the spraying time, the smaller the number of bacteria to be cultured. Furthermore, comparing the growth rates of the bacteria in the medium after the 24-hour spray treatment of FIGS. 6 and 7, the bacteria cultivated after the 24-hour spray treatment of FIG. 7 in which the concentration of hypochlorous acid water was doubled were found. It turns out that there are few. That is, the bactericidal action on the surface of fruits and vegetables is related to the spraying time and the concentration of hypochlorous acid water. Therefore, the bactericidal action on the surface of fruits and vegetables can be enhanced by setting an appropriate spraying time and concentration according to the production and distribution process of fruits and vegetables, the type of fruits and vegetables, and the like.

Furthermore, the inventors have experimentally verified the bactericidal action of the vaporized sterilizing water used in the second sterilization step. In this experiment, Botrytis cinerea spores were dissolved in physiological saline, then subdivided into petri dishes to prepare a sample, and this sample was placed in a booth of about 1 m ³ and vaporized hypochlorite in the booth. After spraying water at a humidity of 50 to 90% for 6 hours, a sample solution was collected and cultured in a medium for about 6 days in an environment of 20 ° C. FIG. 8 is a photograph in which the above experiment was carried out three times (N1 to N3) and the medium in which the bacterium was cultured was photographed. For comparison, in the culture results of the sample treated with the vaporization spray of water, the bacteria propagated on the entire surface of the medium in the same manner as the result of culturing the physiological saline solution in which the spores of Botrytis cinerea were dissolved without treatment. On the other hand, in the results of culturing after treatment with vaporization spray of hypochlorous acid water, no bacterial growth was observed. Therefore, it is shown that this embodiment is effective as spatial sterilization.

(Second Embodiment)
The second embodiment will be described. This embodiment is different from the first embodiment in the configuration of the first sterilization device 1 and the second sterilization device 2 and the flow of the first sterilization step and the second sterilization step. The same elements as those in the first embodiment are designated by the same reference numerals, and duplicate description may be omitted.

FIG. 9 is a diagram schematically showing a configuration example of the first sterilizer 1 according to the present embodiment. In the first sterilizer 1 shown in this figure, instead of the tank 10, the pipe 11, and the pump 12 shown in FIG. 3, the first tank 10a, the second tank 10b, the first pipe 11a, the second pipe 11b, and the first It includes one pump 12a and a second pump 12b.

The first tank 10a stores hypochlorite water, which is an example of electrolyzed water (or sterilizing water). One end of the first pipe 11a is connected to, for example, the bottom surface of the first tank 10a, and the other end is connected to the spray device 13. The first pump 12a functions as a liquid feeding device for supplying the hypochlorite water of the first tank 10a to the spraying device 13, and is provided in the first pipe 11a. The first pump 12a can adjust the flow rate of the hypochlorous acid water sent to the spraying device 13 by, for example, variable control of the rotation speed.

The second tank 10b stores alkaline electrolyzed water, which is an example of electrolyzed water. As the alkaline electrolyzed water, for example, an aqueous sodium hydroxide solution can be used. One end of the second pipe 11b is connected to, for example, the bottom surface of the second tank 10b, and the other end is connected to the spray device 13. The second pump 12b functions as a liquid feeding device that supplies the alkaline electrolyzed water of the second tank 10b to the spraying device 13, and is provided in the second pipe 11b. The second pump 12b can adjust the flow rate of the alkaline electrolyzed water sent to the spray device 13 by, for example, variable control of the rotation speed.

The hypochlorous acid water in the first tank 10a and the alkaline electrolyzed water in the second tank 10b are manually supplied through the water supply ports provided in the first tank 10a and the second tank 10b, respectively, or the first tank 10a and the second tank 10a and the second tank. It is appropriately replenished by a power source such as a pump via a water supply pipe connected to 10b. The liquid transfer from the first tank 10a and the second tank 10b to the spraying device 13 may be performed by using the head pressure or the like. In this case, for example, the flow rates of the hypochlorous acid water and the alkaline electrolyzed water sent to the spraying device 13 can be adjusted by providing solenoid valves having a variable opening degree in the first pipe 11a and the second pipe 11b, respectively. it can.

The controller 14 controls the first pump 12a and the second pump 12b, respectively. When the hypochlorite water of the first tank 10a is supplied to the vaporizer 16 by the first pump 12a with the second pump 12b stopped, the hypochlorite water can be vaporized in the vaporizer 16. At the same time, the vaporizer 16 also generates a mist of hypochlorous acid water having a relatively small particle size. On the other hand, when the alkaline electrolyzed water of the second tank 10b is supplied to the vaporizer 16 by the second pump 12b with the first pump 12a stopped, the alkaline electrolyzed water can be vaporized in the vaporizer 16. At the same time, the vaporizer 16 also generates a mist of alkaline electrolyzed water having a relatively small particle size. As described above, the first sterilizer 1 according to the present embodiment selectively sprays vaporized hypochlorous acid water and vaporized alkaline electrolyzed water by selective control of the first pump 12a and the second pump 12b. can do.

FIG. 10 is a diagram schematically showing a configuration example of the second sterilizer 2 according to the present embodiment. In the second sterilizer 2 shown in this figure, instead of the tank 20, the pipe 21, and the pump 22 shown in FIG. 4, the first tank 20a, the second tank 20b, the first pipe 21a, the second pipe 21b, and the second It includes one pump 22a and a second pump 22b.

The first tank 20a stores hypochlorite water, which is an example of electrolyzed water (or sterilizing water). One end of the first pipe 21a is connected to, for example, the bottom surface of the first tank 20a, and the other end is connected to the vaporizer 23. The first pump 22a functions as a liquid feeding device for supplying the hypochlorous acid water in the first tank 20a to the vaporizer 23, and is provided in the first pipe 21a. The first pump 22a can adjust the flow rate of the hypochlorous acid water sent to the vaporizer 23, for example, by variable control of the rotation speed. The hypochlorous acid water sent to the vaporizer 23 is dropped onto the vaporizer 26.

The second tank 20b stores alkaline electrolyzed water, which is an example of electrolyzed water. As the alkaline electrolyzed water, for example, an aqueous sodium hydroxide solution can be used. One end of the second pipe 21b is connected to, for example, the bottom surface of the second tank 20b, and the other end is connected to the vaporizer 23. The second pump 22b functions as a liquid feeding device that supplies the alkaline electrolyzed water of the second tank 20b to the vaporizer 23, and is provided in the second pipe 21b. The second pump 22b can adjust the flow rate of the alkaline electrolyzed water sent to the vaporizer 23, for example, by variable control of the rotation speed. The alkaline electrolyzed water sent to the vaporizer 23 is dropped onto the vaporizer 26.

The hypochlorous acid water in the first tank 20a and the alkaline electrolyzed water in the second tank 20b are manually supplied through the water supply ports provided in the first tank 20a and the second tank 20b, respectively, or the first tank 20a and the second tank 20b. It is appropriately replenished by a power source such as a pump via a water supply pipe connected to 20b. The liquid transfer from the first tank 20a and the second tank 20b to the vaporizer 23 may be performed by using the head pressure or the like. In this case, for example, the flow rates of the hypochlorous acid water and the alkaline electrolyzed water sent to the vaporizer 23 can be adjusted by providing solenoid valves with variable openings in the first pipe 21a and the second pipe 21b, respectively. it can.

The controller 24 controls the first pump 22a and the second pump 22b, respectively. When the hypochlorous acid water in the first tank 20a is supplied to the vaporizer 26 by the first pump 22a with the second pump 22b stopped, the vaporizer 26 generates a gas in which the hypochlorite water is vaporized. be able to. The vaporizer 26 vaporizes the hypochlorous acid water, and at the same time, generates a mist of the hypochlorous acid water having a relatively small particle size. On the other hand, when the alkaline electrolyzed water of the second tank 20b is supplied to the vaporizer 26 by the second pump 22b with the first pump 22a stopped, the vaporizer 26 generates a gas obtained by vaporizing the alkaline electrolyzed water. Can be done. The vaporizer 26 vaporizes the alkaline electrolyzed water, and at the same time, generates a mist of the alkaline electrolyzed water having a relatively small particle size. As described above, the second sterilizer 2 according to the present embodiment vaporizes the gas obtained by vaporizing the hypochlorous acid water and the alkaline electrolyzed water by the selective control of the first pump 22a and the second pump 22b. It is possible to selectively release gas or the like.

The flow of the sterilization process according to the present embodiment using the first sterilizer 1 and the second sterilizer 2 will be described with reference to the flowchart of FIG.
When the operation start instruction is input (step S21), the controller 14 of the first sterilizer 1 first sprays alkaline electrolyzed water for a predetermined time (step S22: first spray step). ). That is, the controller 14 operates the second pump 12b, the carburetor 16, and the fan 17 for a predetermined time with the first pump 12a stopped. As a result, the alkaline electrolyzed water in the second tank 10b is vaporized by the vaporizer 16 to become a gas containing, for example, mist, and is sprayed from the exhaust port 15b. The sprayed alkaline electrolyzed water removes organic substances and the like adhering to the surface of fruits and vegetables P.

Subsequently, the controller 14 sprays the hypochlorite water for a predetermined time (step S23: second spraying step). That is, the controller 14 operates the first pump 12a, the carburetor 16, and the fan 17 for a predetermined time with the second pump 12b stopped. As a result, the hypochlorous acid water in the first tank 10a is vaporized by the vaporizer 16 to become vaporized sterilized water containing, for example, mist, and is sprayed from the exhaust port 15b. The surface of fruits and vegetables P is sterilized by this vaporized sterilizing water.

After steps S22 and S23, the controller 14 determines whether or not the timing for ending processing has arrived (step S24). The timing of processing end is the same as that of the first embodiment. If the timing for ending the processing has not arrived (NO in step S24), the controller 14 executes steps S22 and S23 again. On the other hand, when the timing of the end of the treatment has arrived (YES in step S23), the controller 14 stops the spraying of the vaporized alkaline electrolyzed water and the vaporized hypochlorite water.

Upon transportation after the first sterilization step (steps S21 to S24), the operator inputs an operation start instruction to the second sterilization device 2 as in the first embodiment (step S25). In response to the input of this instruction, the controller 24 discharges the vaporized sterilizing water and mist into the space 5 for a predetermined time (step S26: first release step). That is, the controller 24 operates the first pump 22a and the fan 27 for a predetermined time with the second pump 22b stopped. As a result, the hypochlorous acid water in the first tank 20a is vaporized by the vaporizer 26, and the vaporized gas is discharged from the exhaust port 25b.

Subsequently, the controller 24 releases the vaporized alkaline electrolyzed water and mist into the space 5 over a predetermined time (step S27: second release step). That is, the controller 24 operates the second pump 22b and the fan 27 for a predetermined time with the first pump 22a stopped. At this time, the alkaline electrolyzed water in the second tank 20b is vaporized by the vaporizer 26, and the vaporized gas is discharged from the exhaust port 25b. As a result, for example, the hypochlorous acid water adhering to the wall portion 4 or the packing container 3 arranged in the space 5 is neutralized, and these corrosions can be prevented. For example, the amount of alkaline electrolyzed water vaporized and released in step S27 may be smaller than the amount of hypochlorous acid water vaporized and released in step S26.

After steps S26 and S27, the controller 24 determines whether or not the timing for ending processing has arrived (step S28). The timing of processing end is the same as that of the first embodiment. If the timing for ending the process has not arrived (NO in step S28), the controller 24 executes steps S26 and S27 again. On the other hand, when the timing of the end of the treatment has arrived (YES in step S28), the controller 24 stops the vaporization and release of the hypochlorite water and the alkaline electrolyzed water. This completes the sterilization process shown in the flowchart.

By using not only hypochlorous acid water but also alkaline electrolyzed water such as an aqueous solution of sodium hydroxide as the electrolyzed water as in the present embodiment, the first sterilization step (steps S21 to S24) and the second sterilization step (step S25). Each of ~ S28) exerts a suitable action.

That is, in the first sterilization step, organic substances and the like adhering to the surface of fruits and vegetables P can be removed by spraying alkaline electrolyzed water, and the sterilizing action of the hypochlorite water sprayed thereafter can be enhanced. On the other hand, in the second sterilization step, the inside of the space 5 can be neutralized and corrosion of the wall portion 4 and the like can be prevented.
In addition to these, the same actions as those of the first embodiment can be obtained from the present embodiment.

In the second embodiment, a method of pre-storing electrolyzed water in the first tank 10a and the second tank 10b of the first sterilizer 1 or the first tank 20a and the second tank 20b of the second sterilizer 2 was used. , A three-chamber electrolyzed water producing apparatus as described in the specification attached to Japanese Patent Application No. 2014-191565 proposed by the present applicant is attached instead of these tanks, and while electrolyzing electrolyzed water, the electrolyzed water is produced. You may spray it. The details of the three-chamber electrolyzed water production apparatus are omitted by quoting Japanese Patent Application No. 2014-191565, and the entire contents thereof are referred to here as a part of the present application.

(Third Embodiment)
A third embodiment will be described. This embodiment is different from the first embodiment in the configuration of the second sterilization apparatus 2 and the flow of the second sterilization step. The same elements as those in the first embodiment and the second embodiment are designated by the same reference numerals, and duplicate description may be omitted.

FIG. 12 is a diagram schematically showing a configuration example of the second sterilizer 2 according to the present embodiment. The second sterilizer 2 shown in this figure is different from that shown in FIGS. 4 and 10 in that it further includes a dehumidifying device 30 for recovering water from the space 5 and a humidity sensor 31.

The dehumidifying device 30 is arranged in the space 5 together with the vaporizing device 23, and includes a condenser 32 and a dehumidifying fan 33 (second fan) that blows air to the condenser 32. In order to distinguish it from the dehumidifying fan 33, the fan 27 is referred to as a vaporization fan 27 (first fan) in this embodiment.

In the example of FIG. 12, the vaporizer 23 and the dehumidifier 30 share the housing 25. That is, the inside of the housing 25 is divided into two spaces by a partition plate 34, the vaporizer 26 and the vaporizer fan 27 are arranged in one of these spaces, and the condenser 32 and the dehumidifying fan 33 are arranged in the other space. ing. The partition plate 34 is provided with a communication hole 34a that communicates these two spaces. The intake port 25a communicates the space where the condenser 32 and the dehumidifying fan 33 are arranged with the outside of the housing 25, and the exhaust port 25b is the space where the vaporizer 26 and the vaporization fan 27 are arranged and the outside of the housing 25. Is in communication. In the example of FIG. 12, the dehumidifying fan 33 is arranged between the intake port 25a and the condenser 32.

For example, a cooling method in which the air sent by the dehumidifying fan 33 is cooled by the condenser 32 can be applied to the dehumidifying device 30. In this case, the dehumidifying device 30 includes a circulation pipe connected to the condenser 32 and a compressor that compresses the refrigerant flowing through the circulation pipe, and heats the air sent by the dehumidifying fan 33 with the refrigerant in the condenser 32. It is cooled by exchange and the water vapor contained in this air is condensed (the refrigerant evaporates). The dehumidifying device 30 can also be applied with a compression method such as isothermally compressing the air taken in from the intake port 25a to condense the water vapor contained in the air. Moisture generated by condensation in the condenser 32 falls into the housing 25 as droplets, and is stored in the lower part of the space for accommodating the condenser 32, for example, surrounded by the housing 25 and the partition plate 34. ..

The air dehumidified by the dehumidifying device 30 reaches the space where the vaporizer 26 is arranged through the communication hole 34a, and is exhausted from the exhaust port 25b to the outside of the housing 25.
The humidity sensor 31 detects the humidity in the space 5 and outputs the detected value to the controller 24. The humidity detected here is, for example, a relative humidity. The controller 24 controls the dehumidifying fan 33 in addition to the pump 22 and the vaporization fan 27.

The timing of executing the dehumidification (dehumidification step) by the dehumidifying device 30 can be, for example, the timing at which the humidity detected by the humidity sensor 31 rises to a threshold value less than a predetermined saturated vapor pressure. After dehumidification is executed when the humidity reaches this threshold value, the vaporized substance of the hypochlorous acid water released into the space 5 can be replaced by further vaporizing the hypochlorous acid water by the vaporizer 23. .. Such a threshold is set, for example, in the range where the relative humidity is 50% or more and less than 100% (saturated vapor pressure). Further, in order to obtain a sufficient moisturizing effect of fruits and vegetables P and prevent dew condensation from occurring in the space 5, the above threshold value is preferably about 80%. The timing of dehumidification can also be determined by factors other than humidity, such as the timing at which a predetermined time has elapsed since the start of vaporization and release of hypochlorous acid water.

The timing of completion of dehumidification can be, for example, the timing at which the humidity detected by the humidity sensor 31 drops to a predetermined threshold value. Such a threshold value is set to a value lower than the threshold value used in determining the timing of dehumidification execution. The timing of completion of dehumidification can also be determined by factors other than humidity, such as the timing at which a predetermined time has elapsed since the start of dehumidification.

The vaporization and release of the hypochlorous acid water by the vaporizer 23 may be performed steadily regardless of the timing of the dehumidification execution by the dehumidifying device 30, or at the same timing as the timing of the dehumidification execution by the dehumidifying device 30. May be executed. Further, the vaporization and release of the hypochlorous acid water by the vaporizer 23 may be executed when the dehumidification by the dehumidifier 30 is not performed, and may be stopped when the dehumidification is performed.

Also in the present embodiment described above, the same action as that of the first embodiment can be obtained. Further, according to the configuration of the present embodiment, the humidity of the space 5 can be controlled, and a humidity environment more suitable for transporting and storing the fruits and vegetables P can be created. Even if a temperature change due to the temperature difference of the outside air occurs in the space 5 during transportation of the fruits and vegetables P, it is generated on the surface and the wall 4 of the fruits and vegetables P in the space 5 by appropriately controlling the humidity of the space 5. Condensation that can occur can be suppressed. Further, the sterilizing ability of the space 5 can be enhanced by recovering the gas released into the space 5 and having a weakened bactericidal action by the dehumidifying device 30 and releasing the fresh gas. If the humidity in the space 5 is high, it becomes difficult for the hypochlorite water to vaporize in the vaporizer 23, but by recovering the water from the space 5 and lowering the humidity, the vaporization of the hypochlorite water in the vaporizer 23 is promoted. can do. In general, hypochlorous acid is immediately activated by contact with organic substances and the like. Therefore, it is extremely important for sterilization management using hypochlorous acid to constantly supply new hypochlorous acid around the object to be sterilized. According to the present embodiment, new vaporized hypochlorous acid can be supplied by recovering the gas and water (water molecules) released into the space 5 by the dehumidifying device 30. Further, the above can be easily realized by controlling the humidity of the space 5.

In the present specification, the term “recovery” includes not only removing gas and water (water molecules) from the space 5 by the dehumidifying device 30, but also discharging gas and water from the space 5. That is, a configuration may be adopted in which gas or water in the space 5 is discharged from a vent or a gap provided in the wall portion 4.

The inventors have experimentally verified the bactericidal action when vaporized sterilizing water is released and the space is dehumidified as in the present embodiment. In this experiment, the purchased okra was placed in a booth of about 1 m ³ , and vaporized hypochlorous acid water was sprayed in the booth for a predetermined time, and then bacteria were collected from the surface of the okra and collected. The fungus was cultured in the medium for about 1 day in an environment of 37 ° C. This experiment was conducted in the case where a dehumidifier was placed in the booth to dehumidify the inside of the booth with the spray of hypochlorite water, and the case where the dehumidifier was not placed. For comparison, bacteria were collected from the surface of okra immediately after purchase, and the collected bacteria were cultured in the same manner.

FIG. 13 is a photograph in which the above experiment was carried out four times (N1 to N4) and the medium in which the bacterium was cultured was photographed. When dehumidification is not performed (“no dehumidification” in the figure), the experimental conditions are that the room temperature in the booth is about 12 ° C, the humidity is 100%, and the effective chlorine concentration of hypochlorous acid water stored in the tank 10 for vaporization. (ACC) is 152 ppm and the experiment time is 24 hours. On the other hand, when dehumidifying (“with dehumidification” in the figure), the experimental conditions are that the room temperature in the booth is about 24 ° C, the humidity is 50 to 90%, and the effective chlorine concentration of hypochlorous acid water for vaporization (ACC). ) Is 152 ppm, and the experiment time is 24 hours. The high room temperature in the booth when dehumidifying is due to the heat generated by the dehumidifier.

In each photograph, the medium is arranged in a circular petri dish, and the whitish part corresponds to the cultured bacteria. Comparing the case where the vaporized hypochlorite water was not sprayed (“no treatment” in the figure) and the case where the vaporized hypochlorite water was sprayed, regardless of the presence or absence of dehumidification. The amount of cultured bacteria was smaller when the vaporized hypochlorous acid water was sprayed. Furthermore, when spraying vaporized hypochlorous acid water, it is more dehumidifying than when dehumidifying is not performed (“electrolyzed water spray without dehumidification” in the figure) (“electrolyzed water spray with dehumidification” in the figure). The amount of bacteria cultured was smaller in "). It is noteworthy that the room temperature when dehumidifying was 24 ° C., and the culture of the bacteria was suppressed despite the environment in which the bacteria were more likely to grow than the 12 ° C. when dehumidifying was not performed.

From this experiment, as in the third embodiment, the dehumidifying device 30 is provided in the second sterilizing device 2, and the vaporized hypochlorous acid water is discharged into the space 5 and the space 5 is dehumidified to sterilize the space 5. Can be seen to improve.

(Fourth Embodiment)
A fourth embodiment will be described. This embodiment is different from the first embodiment, the second embodiment, and the third embodiment in the configuration of the second sterilizer 2. The same elements as those in the above-described embodiments may be designated by the same reference numerals, and duplicate description may be omitted.

FIG. 14 is a diagram schematically showing a configuration example of the second sterilizer 2 according to the present embodiment. In the second sterilizer 2 shown in this figure, the condenser 32 of the dehumidifying device 30 is formed by a photocatalyst, and the dehumidifying device 30 includes an ultraviolet lamp 35 (irradiating device) that irradiates the condenser 32 with ultraviolet rays. It is different from the one shown in 12.

As the photocatalyst forming the condenser 32, for example, titanium oxide can be used. The ultraviolet lamp 35 is turned on and off under the control of the controller 24. When the condenser 32 formed of the photocatalyst is irradiated with ultraviolet rays from the ultraviolet lamp 35, it oxidizes the organic gas (growth promoting gas) such as ethylene gas contained in the air taken in from the intake port 25a. Disassemble.

The sterilization process using the second sterilizer 2 according to the present embodiment can be performed in the same procedure as that shown in the flowchart of FIG. 5, for example. The controller 24 continuously turns on the ultraviolet lamp 35, for example, during the second sterilization step. Alternatively, the controller 24 may turn on the ultraviolet lamp 35 at a predetermined timing in the sterilization process, for example, when the dehumidifying operation is executed by the dehumidifying device 30.

The fruits and vegetables P are spoiled by ethylene gas, and the spoiled fruits and vegetables P generate ethylene gas. With the configuration of the present embodiment, such ethylene gas can be removed by the condenser 32 formed by the photocatalyst, so that the fruits and vegetables P can be kept fresher.
In addition, according to the present embodiment, the same action as that of the third embodiment can be obtained.

(Fifth Embodiment)
A fifth embodiment will be described. This embodiment is different from each of the above-described embodiments in the configuration of the vaporizer 23. The same elements as in each embodiment are designated by the same reference numerals, and duplicate description may be omitted.

FIG. 15 is a diagram schematically showing a configuration example of the vaporizer 23 according to the present embodiment. The vaporizer 23 shown in this figure is different from that shown in FIGS. 4, 10, 12, and 14 in that it includes cooling fins 40.

A plurality of cooling fins 40 are formed of, for example, a metal material, and are arranged in the vicinity of the exhaust port 25b. The gas released from the exhaust port 25b is cooled by the cooling fins 40, and the water vapor contained in the gas is condensed. The water generated thereby becomes, for example, droplets and adheres to or drops on the cooling fins 40. The vaporizer 23 may further include a container or the like that receives water droplets falling from the cooling fins 40.

According to the configuration of the present embodiment, the cooling fins 40 remove the moisture of the gas released into the space 5 from the exhaust port 25b to wet the surface of the object such as the fruit and vegetable P and the packing container 3 containing the fruit and vegetable P. It can be prevented and the humidity can be lowered to prevent an excessive rise in the humidity of the space 5.
The first sterilizer 1 shown in FIGS. 3 and 9 may be provided with the same cooling fins 40 as in the present embodiment.

(Sixth Embodiment)
The sixth embodiment will be described. In the present embodiment, a method of injecting a bactericidal component (vaporized electrolyzed water, vaporized substance) into the inside of the packing container 3 by differential pressure ventilation is disclosed. The same elements as in each embodiment are designated by the same reference numerals, and duplicate description may be omitted.

FIG. 16 is a diagram showing an outline of differential pressure ventilation according to the present embodiment. Here, in the above-mentioned second sterilization step, a case where the packing container 3 arranged in the space 5 surrounded by the wall portion 4 is to be ventilated will be illustrated. However, the differential pressure ventilation according to the present embodiment can be applied to various other situations such as when storing an object in a warehouse or the like.

In the example of FIG. 16, the space 5 is divided into two by the partition member 6. Hereinafter, one of these two spaces will be referred to as space 5A, and the other will be referred to as space 5B. The partition plate 6 is provided with a large number of ventilation holes. Therefore, the spaces 5A and 5B communicate with each other through these ventilation holes, and the spaces 5A and 5B may be the same space.

A second sterilizer 2 is arranged in the space 5A, and a packing container 3 is arranged in the space 5B. The packing container 3 has a large number of vents, and the inside of the packing container 3 and the space 5 (space 5B) communicate with each other through the vents.

The packing container 3 shown in FIG. 16 includes, for example, a through box and a cardboard box used for distribution, and has at least two vents inside for allowing bactericidal components to enter and exit, and is directed from the inside to the outside of the packing container 3. Any structure may be used as long as the pressure is lower than that of the space 5 when the flow of air is generated.

Specifically, the packing container 3 shown in FIG. 16 includes a first side surface F1 and a second side surface F2 facing the first side surface, and one or a large number of the first side surface F1 and the second side surface F2. Vents are provided. Similarly, vents may be provided on the other two side surfaces, the upper surface and the bottom surface connecting the first side surface F1 and the second side surface F2.

The example of FIG. 16 is a case where the upper part of the packing container 3 is open, and in the example of FIG. 16, the fruits and vegetables P are housed inside the packing container 3, and the opening of the packing container 3 is the lid material 7. It is closed. The lid material 7 may be formed of, for example, a resin material or a metal material so as to cover the opening of the packing container 3, or may be a flexible sheet material. A vent may be provided in the lid material 7, or if the internal storage acts as a kind of sheet and the same differential pressure effect as when the lid 7 is placed can be obtained when ventilated. The lid 7 may be omitted.

In addition, because the vent is too large, even in a packaging container with a structure that does not decompress the inside due to ventilation as it is, by covering a part or the entire surface of the side surface, bottom surface and top surface with a flexible sheet material, the inside can be decompressed when ventilation In this case, this may also be regarded as the packing container 3.

In the space 5B, the ventilation fan 8 is arranged so as to face the second side surface F2 of the packing container 3. The ventilation fan 8 generates an air flow from the inside of the packing container 3 to the outside. As a result, the pressure inside the packing container 3 is reduced.

The sterilizing component supplied from the second sterilizing device 2 is supplied from the space 5A to the space 5B through the vent of the partition member 6. Since the inside of the packing container 3 is depressurized more than the space 5A with the operation of the ventilation fan 8, this bactericidal component is injected into the inside of the packing container 3 through the vent of the first side surface F1. If vents are provided on the other sides of the packing container 3, the bactericidal component is also injected through the vents on these sides. Further, if the bottom surface of the packing container 3 is provided with a vent, and the bottom surface is in a state of floating from the mounting surface of the packing container 3, the bactericidal component can be injected from the vent on the bottom surface.

The air inside the packing container 3 is discharged from the second side surface F2 to the space 5B by the action of the ventilation fan 8. As a result, at least a part of the bactericidal component inside the packing container 3 is discharged.

The inventors have experimentally verified the effect of such differential pressure ventilation. FIG. 17 is a graph showing the results of this experiment. In this experiment, the amount of sterilized (hypochlorous acid) component injected into the packing container 3 was measured in the three patterns of cases A1, A2, and A3. The unit of the sterilization (hypochlorous acid) component injection amount is expressed as [μg / min * m ² ], and the sterilization (hypochlorous acid) component that reaches the unit area inside the packing container 3 of FIG. 16 in a unit time. It was defined by the injection volume.

For the packing container 3, a box having no upper surface and having vents on all sides and the bottom surface was prepared. The amount of sterilizing component reached when the sterilizing component is released from the second sterilizing device 2 installed in space 5A is measured by arranging the packing container 3 in which nothing is stored inside in case A1 in space 5B and measuring the amount reached. Then, in the case A2, the amount of arrival inside the packing container 3 when the packing container 3 is placed in the space 5B with the fruits and vegetables P filled inside is measured, and in the case A3, the side surface after filling the inside with the fruits and vegetables P. Measure the amount reached when the vents other than the two surfaces of F1 and F2 are closed, the upper surface is closed with the lid material 7, the packing container 3 is arranged in the space 5B, and differential pressure ventilation is performed by the ventilation fan 8. did.

The results of this experiment, the bactericidal component injection volume, in Case A1 about 93μg / (min * ^{m 2),} and the about the case ^{A2 7μg / (min * m 2} ) , and the about the case A3 97μg / (min * ^{m 2} ).

That is, in the packing container 3 filled with fruits and vegetables P, the injection amount is small in the case of case A2 in which differential pressure ventilation is not performed, but in the case of case A3 in which differential pressure ventilation is performed, the empty packing container 3 (case). It can be seen that an injection amount equal to or greater than that of A1), that is, an injection amount equal to or greater than that when placed in space 5 without being placed in a packing container can be realized.

Actually, it is assumed that the packing container 3 is transported or stored in a state of being stacked in a plurality of stages. Therefore, the effect of differential pressure ventilation was verified even when the packing containers 3 were stacked in a plurality of stages. FIG. 18 is a diagram showing an outline of this experiment. For the packing container 3, a box having no upper surface and having vents on all sides and the bottom surface was prepared. In this experiment, in the three patterns of cases B1, B2, and B3, the amount of bactericidal component injected into each of the stacked packing containers 3 [μg / min * m ² ] was measured.

In the case B1, the packing containers 3 in which nothing was stored were stacked in three stages and arranged in the space 5B, and the differential pressure ventilation by the ventilation fan 8 was not performed. In the case B2, the vent on the side surface of the packing container 3 in which nothing is stored is closed, and the lid material 7 having a vent on the upper surface of the upper surface of the three-tiered stack is arranged in the space 5B by stacking three tiers. Differential pressure ventilation was performed by the ventilation fan 8 in the covered state. In the case B3, with the fruits and vegetables P filled inside, the vents on the side surfaces of the packing container 3 are closed in the same manner as in the case B2, three layers are stacked and arranged in the space 5B, and further on the upper surface of the upper layer of the three layers. Differential pressure ventilation was performed by the ventilation fan 8 with the lid material 7 having a vent covered. Each of the packing containers 3 used here is provided with a vent on the bottom surface. Therefore, even in the stacked state, the inside of each packing container 3 is in communication, and the bactericidal component injected from the upper surface escapes from the lower surface. In the cases B2 and B3, the ventilation fan 8 is arranged so as to face the lower packing container 3.

FIG. 19 is a graph showing the results of the experiment shown in FIG. In case B1, many bactericidal components could be injected into the upper packing container 3, but the injection amount into the middle packing container 3 was significantly smaller than that in the upper packing container 3, and the injection amount into the lower packing container 3 was further increased. It has decreased. In case B2, the injection amount was significantly increased as compared with case B1 in all of the upper, middle, and lower stages. The injection amounts in the middle and lower stages were comparable to the injection amounts in the upper stage. In case B3, as in case B2, a high injection amount could be obtained in all of the upper, middle and lower stages. From this experimental result, a good bactericidal component injection amount can be obtained by performing the differential pressure ventilation according to the present embodiment even when a plurality of packing containers 3 are stacked and the fruits and vegetables P are filled inside. It turns out that it can be done.
The differential pressure ventilation according to this embodiment can be combined with any of the above-described embodiments.

Although some embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other embodiments, and various omissions, replacements, and changes can be made without departing from the gist of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are also included in the scope of the invention described in the claims and the equivalent scope thereof.

For example, the second sterilization step disclosed in each embodiment may be performed not only during the transportation of the fruits and vegetables P contained in the packing container 3, but also when the fruits and vegetables P are stored after their arrival.
In addition, the first sterilization step and the second sterilization step disclosed in each embodiment can be appropriately combined with other steps. For example, when the fresh food to be sterilized is washable like root vegetables, a washing step may be added in place of the first sterilization step or in combination with the first sterilization step.

P ... Fruits and vegetables, L1 ... Sterilization place, L2 ... Transportation means, 1 ... First sterilizer, 2 ... Second sterilizer, 3 ... Packing container, 4 ... Wall, 5 ... Space, 10, 20 ... Tank, 11, 21 ... Piping, 12, 22 ... Pump, 13 ... Sprayer, 14, 24 ... Controller, 16, 26 ... Vaporizer, 17, 27 ... Fan, 23 ... Vaporizer.

Claims (19)

A method of sterilization in the distribution process of objects including fruits and vegetables or fresh flowers that are shipped after being harvested at the growing place, transported by means of transportation, and stored or sold at the destination.
Sterilized water vaporized by a vaporizer when a plurality of breathable packing containers containing the object are stacked and arranged in a space surrounded by a wall in a state where the inside is communicated and transported or stored. by the Rukoto is circulated in the space by the fan, the sterilization step of sterilizing said space,
The plurality of packing containers are arranged in the space together with the plurality of packing containers, and an air flow from the inside of the plurality of packing containers toward the inside of the space is generated by the decompression means facing any of the plurality of packing containers. A decompression step in which the vaporized sterilizing water in the space is distributed to the inside of each of the plurality of packing containers by depressurizing the inside of the packing container.
A sterilization method comprising. The depressurizing means includes a ventilation fan that generates a flow of air from the inside of the packing container to the outside to depressurize the inside of the packing container.
The sterilization method according to claim 1, wherein the sterilization method is characterized by the above. The decompression means faces the side surface of the packing container having a vent.
The sterilization method according to claim 1 , wherein the sterilization method is characterized by the above. Wherein the plurality of packaging containers have a vent in the bottom surface, the interior of the plurality of packaging containers in communication through the vent,
The decompression means faces the packing container at the bottom.
The sterilization method according to claim 1 , wherein the sterilization method is characterized by the above. The sterilizing water used in the sterilizing step contains vaporized sterilizing water and liquid mist, and the particle size of the liquid mist that does not wet the surface of the object is 50 μm or less.
The sterilization method according to claim 1, wherein the sterilization method is characterized by the above. The sterilizing step, the water recovered from the space, dehumidifying steps including keeping the humidity of the space 50 to 90%
The sterilization method according to claim 1, wherein the sterilization method is characterized by the above. The sterilizing water used in the sterilization step is acidic electrolyzed water and alkaline electrolyzed water.
The sterilization step
The first release step of vaporizing the acidic electrolyzed water and releasing it into the space to sterilize the space,
After the first release step, the alkaline electrolyzed water is vaporized and released into the space to neutralize the space.
The sterilization method according to claim 1, wherein the sterilization method comprises. In the sterilization step, water contained in the vaporized sterilizing water is removed by providing fins for cooling the gas and condensing water vapor at the exhaust port of the device that discharges the vaporized sterilizing water from the exhaust port.
The sterilization method according to claim 1, wherein the sterilization method is characterized by the above. The surface of an object containing fruits and vegetables or fresh flowers that is shipped after being harvested at the habitat, transported by means of transportation, and stored or sold at the destination, and which requires prevention of bacterial growth or adhesion. In a sterilization system that sterilizes in a space surrounded by walls
A vaporizer for vaporizing the electrolytic water,
When a plurality of breathable packing containers containing the object are stacked and arranged in the space in a state where the inside is communicated, and transported or stored, the electrolyzed water vaporized by the vaporizer is introduced into the space. With a fan that circulates in
The plurality of packing containers are arranged in the space together with the plurality of packing containers and face one of the plurality of packing containers to generate an air flow from the inside of the plurality of packing containers toward the inside of the space. A decompression means for decompressing the inside of each of the
The fan by circulating the Riki of the electrolytic water in the space, respectively the interior of the plurality of packing containers by vacuum by the pressure reducing means of said plurality of packaging containers vaporized electrolytic water in said space A sterilization system characterized in that the object is sterilized by spreading it inside the container. The depressurizing means includes a ventilation fan that generates a flow of air from the inside of the packing container to the outside to depressurize the inside of the packing container.
9. The sterilization system according to claim 9 . The ventilation fan faces the side surface of the packing container having a vent.
The sterilization system according to claim 10 . Wherein the plurality of packaging containers have a vent in the bottom surface, the interior of the plurality of packaging containers in communication through the vent,
The ventilation fan faces the packing container at the bottom.
The sterilization system according to claim 10 . A dehumidifying device that recovers moisture from the space and keeps the humidity of the space at 50 to 90% is further provided.
9. The sterilization system according to claim 9. A storage method in which an object including fruits and vegetables or fresh flowers, which is shipped after being harvested at the habitat, transported by means of transportation, and stored or sold at the destination, is stored in a space surrounded by a wall.
When a plurality of breathable packing containers containing the object are stacked and arranged in the space in a state where the inside is communicated for transportation or storage, the vaporized substance of the electrolyzed water vaporized by the vaporizer is used as a fan. A circulation step that circulates in the space by
A decompression means arranged in the space together with the plurality of packing containers and facing any of the plurality of packing containers generates an air flow from the inside of the plurality of packing containers toward the inside of the space to generate the plurality of packing containers. by reducing the pressure inside the respective packaging container, a depressurizing step to spread the vapors in the space within each of the plurality of packaging containers,
Including
By circulating the vaporized substance, the space is sterilized.
A storage method characterized in that the object is sterilized by spreading the vaporized substance inside the packing container by the decompression step. The decompression means faces the side surface of the packing container having a vent.
The storage method according to claim 14 , characterized in that. Wherein the plurality of packaging containers have a vent in the bottom surface, the interior of the plurality of packaging containers in communication through the vent,
The decompression means faces the packing container at the bottom.
The storage method according to claim 14 , characterized in that. The circulation step comprises recovering moisture from the space and keeping the humidity of the space at 50-90% .
The storage method according to claim 14 , characterized in that. The circulation step
And to sterilize the floating bacteria in the vaporizer for vaporizing the electrolytic water with water electrolytic water, by contacting the airborne bacteria floating in the space,
By dispersing the vaporized substance in the space, the floating bacteria in the space can be sterilized.
To sterilize the surface bacteria existing on the wall, the floor, or the surface of the object by allowing the vaporized substance to reach the surface of the wall, the floor, or the object arranged in the space.
The storage method according to claim 14 , wherein the storage method comprises. The electrolyzed water in the circulation step includes acidic electrolyzed water and alkaline electrolyzed water.
The circulation step
To sterilize the space by vaporizing the acidic electrolyzed water and releasing it into the space.
To neutralize the space by vaporizing the alkaline electrolyzed water and releasing it into the space.
The storage method according to claim 14 , wherein the storage method comprises.

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