JPH09149A - Immersion water for holding freshness of perishable food, its production and producing device therefor - Google Patents

Abstract

PURPOSE: To provide an immersion water capable of maintaining the freshness of a perishable food for a longer time than conventional water, excellent in sanitariness and useful for holding the freshness of the perishable food, to provide a method for producing the immersion water, and further to provide a device for producing the immersion water. CONSTITUTION: The immersion water for holding the freshness of a perishable food is produced by the electrolysis of sea water or water containing an electrolyte such as salt to reduce Escherichia call and general bacteria and further contains hypochloric acid and/or sodium hypochlorite produced by the electrolysis.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to immersion water for keeping the freshness of fresh products used for storage, transportation, processing, etc. of marine products, a method for manufacturing the same, and an apparatus for manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, water has been used for storage, transportation, processing, etc. of fresh fish, and shellfish such as oysters, shrimp, crabs, shrimp,
Even seafood such as sea urchins are soaked in water and stored alive. And, fresh water is usually used as water for this purpose.

On the other hand, it is not preferable to keep aquatic products in fresh water for a long time in the storage process or the processing process in order to maintain their freshness as compared with the case where the water contains salt. Well water along the coast and shallow wells (mixed seawater and groundwater) may be used.

However, since water containing seawater is contaminated with coliform bacteria and general bacteria (general viable bacteria), it may cause hygiene problems when used for storing marine products.

[0005]

SUMMARY OF THE INVENTION Therefore, the present invention
It is an object of the present invention to provide immersion water for maintaining the freshness of fresh products which can maintain freshness and is excellent in hygiene as compared with conventional ones, a method for producing the same, and an apparatus for producing the same.

[0006]

In order to solve the above-mentioned problems, the present invention employs the following technical means.

The immersion water for keeping the freshness of the fresh products of the present invention is reduced in coliform bacteria and general bacteria by electrolysis of seawater or water containing an electrolyte such as salt, and
It is characterized by containing hypochlorous acid or / and sodium hypochlorite produced by electrolysis.

The ice-making water for keeping the freshness of this fresh product is
It is characterized in that immersion water for keeping the freshness of the fresh product is frozen and used. The ice for keeping the freshness of the fresh product is characterized in that the immersion water for keeping the freshness of the fresh product is frozen.

The cleaning water for maintaining the freshness of this fresh product is
The immersion water for maintaining the freshness of the fresh product is used for washing during processing of the fresh product.

Further, the method for producing immersion water for keeping the freshness of the fresh product reduces the coliform bacteria and general bacteria of seawater or water containing electrolytes such as salt and reduces hypochlorous acid and / or hypochlorous acid. It is characterized by electrolyzing so as to generate acid soda. It is also possible to carry out by separating and removing coliform bacteria and general bacteria and pollutants by filtering water containing an electrolyte such as seawater or salt with a microporous thin film.

This apparatus for producing immersion water for keeping the freshness of fresh products reduces the coliform bacteria and general bacteria of water containing electrolytes such as seawater or salt and reduces hypochlorous acid and / or sodium hypochlorite. It is characterized by comprising an electrolysis mechanism for producing It can also be carried out by providing a microporous thin film for separating and removing pollutants from coliform bacteria and general bacteria of water containing an electrolyte such as seawater or salt.

[0012]

The present invention has the following functions.

When electrolyzing seawater or water containing an electrolyte such as salt, coliform bacteria and general bacteria (general viable bacteria) are reduced or eliminated by an oxidative decomposition reaction, and electrolysis causes hypochlorous acid (HClO) and / or Since sodium hypochlorite (NaClO → Na ⁺ + ClO ⁻ ) is produced,
The activity of coliform bacteria and general bacteria on the soaked perishable product can be suppressed or stopped by hypochlorous acid and / or sodium hypochlorite.

Further, when the coliforms and general bacteria of water containing electrolytes such as salt water or salt and general pollutants are separated and removed by a microporous thin film, immersion water for maintaining a fresher freshness of fresh products can be obtained. Can be obtained.

Further, when ice for keeping freshness of fresh products is produced from immersion water for keeping freshness of fresh products, coliform bacteria and general bacteria are reduced or disappeared in the ice, which is excellent in hygiene and hypochlorous. Since it contains chloric acid or / and sodium hypochlorite, if it is used for keeping cold fresh foods, etc., even if fresh water is used as immersion water for fresh foods, Due to the antibacterial action of chlorous acid and / or sodium hypochlorite, the freshness of fresh products is excellently maintained.

When this immersion water for maintaining the freshness of the fresh product is used as a cleaning water for washing away the blood from the fish body when processing the fresh product, for example, when taking out the built-in of fresh fish, etc. By exerting the bactericidal action of chlorous acid and / or sodium hypochlorite on the fillets of fresh products, it becomes more preferable in terms of food hygiene.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The configuration of the present invention will be described below with reference to the drawings showing an embodiment.

As shown in FIG. 1, the electrolysis mechanism 1 of this embodiment has an electrolytic passage 2. That is,
A cathode plate 4 (cathode electrode) is arranged on both sides of the anode plate 3 (anode electrode), and an electrolytic passage 2 is formed between these electrodes. A current is supplied to the anode plate 3 and the cathode plate 4 by a known rectifier. The distance between the anode plate 3 and the cathode plate 4 can be preferably set within a range of about 1 to 10 mm, but in the following examples, it is set to 5 mm, and the electrolytic passages 2 connected in series are connected. The total length is set to 180 mm. The electrode area of the electrolysis passage 2 is 3 dm ² , and a voltage of about 5 V is applied to supply a constant current DC 12 Amp as the output of the rectifier.

A packing 5 is interposed between both electrodes to prevent a short circuit, and the packing 5 has a frame shape in which the inside is hollowed out leaving an externally assembled portion. The hollowed-out internal portion forms the electrolytic passage 2. A stainless steel plate 8 is provided outside the both cathode plates 4 with a packing 6 and a vinyl chloride plate 7 interposed therebetween.

A hole H that penetrates below one of the stainless steel plates 8 is provided for the seawater or water containing an electrolyte such as salt by a metering pump.
Flow through the holes H passing through the vinyl chloride plate 7 and the cathode plate 4, respectively, and come into contact with the anode plate 3, and the electrolytic passage 2 between the cathode plate 4 and the anode plate 3 (the portion inside the packing 5). ), Through a hole H penetrating above the anode plate 3 to reach the opposite surface of the anode plate 3. The cathode plate 4 and the anode plate 3 on the opposite surface side
Through the electrolytic passage 2 (inner portion of the packing 5) between the cathode plate 4, the vinyl chloride plate 7, and the stainless steel plate 8 and through holes (not shown) penetrating below each of them. To do.

A plurality of electrolytic modules (replaceable components) having such a structure were formed.

Anode plate 3 and cathode plate 4 defining the electrolytic passage 2.
The electrode polarities of and were made variable by a known electric method, and were changed at regular intervals. By doing so, it is possible to prevent the charged substance in the flowing water of the electrolytic passage 2 from being deposited and grown on the corresponding oppositely charged electrode. Also, when the polarities of both electrode plates are fixed, only the electrode plate selected on the anode side will melt away, which causes a one-sided phenomenon, but by changing the electrode polarity, the side that became the anode will melt away. To go. Therefore, the rate of wear of both electrodes over time can be made substantially equal.

By the way, since water containing seawater, such as seawater and semi-seawater, contains salt (NaCl), when electrolyzed, coliform bacteria, general bacteria and pollutants contained therein due to oxidative decomposition reaction. Sterilized to reduce or disappear.

[0024] In addition, after the electrolysis treatment, such as seawater or salt
Hypochlorous acid (HClO) formed in water containing electrolyte
Or / and sodium hypochlorite (NaClO → Na⁺+ C
10 ^-) Is included, and this hypochlorous acid or / and the following
Due to the bactericidal action of sodium chlorite, the large intestine against fresh products
It is possible to suppress the activities of bacterial groups and general bacteria.
Furthermore, water-soluble pollution that cannot be removed by mechanical filtration.
Substances are also made cleaner by oxidation decomposition by electrolysis.
You.

In this way, clean and sterilizing water can be obtained from seawater or water containing electrolytes such as salt, and this can be used as immersion water for fresh products.
The use of seawater-containing water such as seawater or semi-seawater as a raw material is advantageous in terms of cost.

Next, the usage state of this embodiment will be described.
Seawater or water containing an electrolyte such as salt causes the following reaction at the anode electrode of the electrolysis mechanism 1.

2Cl ⁻ → Cl ₂ + 2e ⁻ (1) Cl ₂ + H ₂ O → HClO + HCl (2) On the other hand, the following reaction occurs at the cathode electrode.

2Na ⁺ + 2e ⁻ → 2Na (3) 2Na + 2H ₂ O → 2NaOH + H ₂ (4) p of water containing an electrolyte such as seawater or salt to be electrolyzed
When H is on the alkaline side, hypochlorous acid (HClO) in water containing electrolytes such as seawater or salt after electrolytic treatment has the formula (4)
Sodium hypochlorite (NaClO) is increased by neutralization with sodium hydroxide (NaOH).

On the other hand, in the case of the acidic side, since sodium hydroxide (NaOH) of the formula (4) is neutralized, the hypochlorous acid (HClO) of the formula (2) exists as it is.

By the way, hypochlorous acid (HClO) is
Sodium chlorite (NaClO → Na ⁺+ ClO^-)Than
The bactericidal effect is several ten times higher. The composition of water after electrolysis is pH
8-9, HClO 20-40%, ClO^-Is 80-9
At 6%, pH 6-7, HClO is 96-80%, ClO
^-Is 4 to 20%.

This water is used for storage, transportation, processing, etc. while suppressing the growth of coliform bacteria and general bacteria of marine products. The water after electrolysis is
Even if the residual chlorine concentration is 1 ppm for spoilage bacteria, 1
Sufficient bactericidal power was observed with a contact time of about a minute.

By the way, it is more preferable to provide a filtration treatment step of seawater or water containing an electrolyte such as salt before, after or both of the electrolysis step. Separation and removal of coliform bacteria and general bacteria and pollutants of water containing electrolytes such as seawater or salt with a microporous thin film can obtain a cleaner immersion water for keeping the freshness of fresh products. .

As the microporous thin film, for example, a membrane filter, a cartridge filter, a hollow filter or the like having a pore size of 1 μm or less can be used. In order to remove other pathogenic bacteria such as Escherichia coli, the pore diameter of the microporous thin film is preferably 0.3 μm or less, and more preferably 0.1 μm or less.

In addition, in order to prevent clogging of fine pores on the filter surface with dirt and the like, and to operate continuously, for a long time, and economically, the filter surface is constantly washed by a known cross-flow method and periodically added. It is preferable to carry out the back washing with compressed air together.

[0035] Next, keeping cold of marine products such as fresh fish
A large amount of ice is used for transportation and processing, and ice water is used for shellfish such as oysters, shrimp, crab, shrimp, sea urchin,
It is kept alive. By the way, the ice used for this purpose was made from fresh water, and when it melted, it returned to fresh water. Immersing marine products in fresh water for a long time is not so preferable for maintaining freshness as compared with the case of using seawater or salt water. Therefore, if possible, it is preferable to use not seawater ice made from fresh water, but seawater ice or saltwater ice produced as well water for making ice from semi-seawater of shallow wells. However, since seawater and well water of a semi-seawater of a shallow well are usually contaminated with bacteria such as coliform bacteria and general bacteria, there was a problem in using it as ice-making water for producing seawater ice. .

However, the immersion water for maintaining the freshness of the fresh product obtained as described above is used as ice making water for maintaining the freshness of the fresh product, and further frozen to retain the freshness of the fresh product. If the ice is used, the coliform bacteria and general bacteria are inactivated, and ice having bactericidal activity can be obtained by hypochlorous acid or sodium hypochlorite.

The ice produced using the substantially sterile clean seawater treated as described above is used, for example, for the storage, transportation, and processing of sterile marine products that have been sterilized in advance. The sterilization effect of the electrolytically treated water gradually decreased with time when it was opened to the air, but when ice was used, almost no decrease with time was observed. (Example 1) Seawater collected as raw water was electrolyzed as follows. The NaCl concentration of this raw seawater was 3.2%.

As shown in FIG. 2, seawater in the raw water tank 9 is electrolyzed by the metering pump P (see FIG. 1).
). 10 is a rectifier. Seawater after electrolysis is stored in the treated water tank 11.

The electrolysis area of the electrolysis mechanism 1 was 3 dm ² for each of the cathode and anode, and the electrolysis module shown in FIG. 1 was 3 dm ^2, and seven electrolysis modules were connected in parallel (total electrode area: 3 × 7 = 21 dm). ² ) was used. The electrolysis conditions were 30 Amp and 3.0 to 3.5 V, and the electrolysis treatment rate was 300 ml / min. (Example 2) As raw water, semi-sea water (well water mixed with sea water) was collected. This half seawater was pumped from a shallow well near the coast, and almost half of the seawater was mixed.
Its NaCl concentration is 1.4% and its electrical conductivity is 25-2.
It was 7 × 1,000 μs / cm. Then, this semi-seawater was first subjected to a filtration treatment using a microporous thin film, and then subjected to an electrolysis treatment in the same manner as in Example 1.

(1) Filtration treatment of semi-seawater As shown in FIG. 3, the filtration treatment involves a hollow fiber filter 13 having a hollow fiber membrane as a microporous thin film 12 (Kuraray Co., Ltd., trade name SF membrane 0.3 μ). It was used. The length of this hollow fiber is 1
m, the filtration area is 7 m ² .

The half seawater is supplied to the hollow fiber filter 13 by the metering pump P. The filtration pressure was set to 1 kg / cm ² , and the filtration treatment was performed at a rate of 2,000 liters / H. By opening the cross-flow valve 14 and setting the ratio of treated water to cross-flow water to about 2: 1, a flow is applied to the filtration surface almost at right angles to the filtration direction, preventing dirt from adhering to the filtration surface. did. Filtered semi-sea water valve
Coming out of fifteen.

Further, by back-washing once a hour for 1 minute while pressurizing with air, clogging of the filtration surface was prevented. 16 is a backwash drain.

(2) Bacterial test before and after filtering seawater The seawater and the one obtained by filtering this seawater were tested for bacteria. Bacterial examination was carried out by the BACcT colony counting method of Shimakyu Pharmaceutical.

A culture dish containing coliform petri dish CC, VRB medium and tetrazolium indicator (TTC) was used.
In addition, a culture dish containing a general viable petri dish AC, a standard agar medium and a tetrazolium indicator (TTC) was used.

As a result of the test, general bacteria of the half seawater used as raw water was 1.1 × 10 ³ , and coliform bacteria was 4.2 × 10 ² . On the other hand, the general bacteria of clean semi-sea water after filtration treatment are 3.
0 × 10, 0 for coliforms. The semi-seawater sampled as raw water was contaminated with coliform bacteria and general bacteria, but it became clean after filtration.

Although the half seawater after the filtration treatment does not contain hypochlorous acid or sodium hypochlorite and has no bactericidal action, most of coliform bacteria and general bacteria are removed. For example, it can be suitably used for storage, transportation, and processing of aseptic marine products that have been sterilized in advance.

When ice is produced by making ice from the half-sea water after the filtration treatment, most of coliform bacteria and general bacteria are removed. For example, aseptic aquatic products that have been sterilized in advance. It can be suitably used for storage, cold storage, transportation, processing, etc.

(3) Electrolysis treatment of semi-sea water after filtration treatment The semi-sea water after filtration treatment was electrolyzed in the same manner as in Example 1.

The electrolysis area of the electrolysis mechanism 1 is 3 dm ² for each of the cathode and the anode, and each of the electrolysis modules shown in FIG. 1 is 3 dm ^2, and seven electrolysis modules are connected in parallel. ² ) was used. The electrolysis conditions were 30 Amp and 3.0 to 3.5 V, and the electrolysis treatment rate was 300 ml / min.

Since the sterilizing power of the treated water depends on the pH of the raw water, the NaCl concentration of fresh water is adjusted to 3.2% and the pH is adjusted with 20% HCl for reference.
Treated water having different residual chlorine concentrations was prepared using the saline solution adjusted to.

The following tests were carried out using the treated water of Examples 1 and 2 above. A) Residual chlorine concentration when left in treated water (pp
Transition test of m) Treated water was stored in a wide-mouthed 100 cc transparent glass bottle, tightly stoppered and left indoors. Then open the lid every two days,
A sample of 0.1 to 1.0 ml was taken with a pipette and the residual chlorine concentration was measured. Table 1 shows the results.

As shown in the results, the residual chlorine concentration in the treated water gradually decreased when left as it was.

B) Residual chlorine concentration (ppm) of ice after ice making
Change test of each of the above electrolyzed water is filled into a plastic bag, 300 ml each,
Ice was made in the ice making room of a large refrigerator. After ice making, it was frozen and stored in an ice state, and it was tested whether or not the residual chlorine concentration, which is an important index for the bactericidal action, decreases with time.

After 12 days from the ice making, it was taken out from the ice making chamber, crushed into ice and put in an ice box. After 30 minutes had elapsed since the ice began to melt, water was successively pipetted to measure the residual chlorine concentration. About 20% was water after 3 hours, about 40% was water after 5 hours, about 60% was water after 8 hours, and 100% was water after 24 hours. Table 2 shows the results.

As shown in the results (comparison with the residual chlorine concentration at 0 days in Table 1), the residual chlorine concentration in ice remained almost unchanged from the time of electrolysis even after 12 days from ice making. . That is, when the ice state was maintained, the function as ice having bactericidal power was sufficiently retained.

The rate of decrease in the residual chlorine concentration after crushing ice and melting was slow, and it took a total of 2 to 3 days for transportation by a cold carrier and storage for landing on which the ice melts slowly. Even so, it is considered that the ice of this example can sufficiently function as sterilized ice.

C) Measurement of Residual Chlorine Concentration of Immersion Seawater of Cold-keeping Live Clams Using Sterilized Ice The sterilized ice stored in the ice making chamber for one month or more was crushed into ice (residual chlorine concentration was not changed at the time of ice making), This sterilized ice was added to the raw seawater in which the clams were immersed, and after a certain period of time, the residual chlorine concentration, which is an index of the sterilization effect, was measured.

The live clams are placed in a Styrofoam container and packed in a transparent wrap (sold in the supermarket), and do not contain seawater. A total of 1 live clam for 3 packs is included. , 050 g was put in a poly bucket containing 1 liter of the sea water (NaCl concentration 3.2%) as it was, and left standing for 3 hours to be acclimated. Then, crushed sterilized ice was put into this poly bucket, and samples were taken after 30 minutes and 24 hours and the residual chlorine concentration was measured. The results are shown in Table 3.

As shown in the item of Example 2 in Table 3, when the residual chlorine concentration of sterilized ice was 63 ppm, when this was added to seawater in which clams were immersed, 2 pp required for sterilization was added.
A concentration of m or more was maintained for 30 minutes.

Further, as shown in the item of Example 1 in Table 3, when the residual chlorine concentration of the sterilized ice was 102 ppm,
The seawater in the poly bucket maintained the residual chlorine concentration of 0.5 ppm even after 24 hours. In other words, when using in such a situation, the residual chlorine concentration of sterilized ice should be 100 p
What was adjusted to pm or more, preferably 300 ppm or more may be used.

D) Bacterial examination of the live clam itself and its soaking water About 150 g (13 to 14) of the same live clam as above in a plastic bag
Individual pieces) and 75 g of seawater itself and 75 g of sterilized ice were added. On the other hand, as a comparative example, about 150 g of the fresh clams
And seawater itself containing 150 g was adjusted in the same manner. After leaving each for 24 hours, the bacteria were tested by the following method.

1 ml each of fresh clams crushed in sterile water and immersion water of "sea water + sterilized ice" in which the live clams were immersed were sampled. As the medium, a standard agar medium was used for general bacteria, and dezoxycholate medium was used for coliforms. General bacteria were evaluated after culturing at 37 ° C. for 48 hours, and coliform bacteria after culturing at 37 ° C. for 24 hours. Bacterial tests were carried out in the same manner for the comparative example. Table 4 shows the results.

As shown in the results, the water soaked in the live clams is more contaminated by bacteria than the live clams themselves, and the pH of the original water of the sterilized ice is 8 units (Table 1).
PH of 8 compared with the reference, Example 1-, reference,)
The following (see Table 1, Examples 2 to, Reference)
Was more effective in sterilization. (Example 3) A semi-sea water was used as raw water, and a production system of immersion water for maintaining the freshness of a fresh product on a practical scale was constructed. This half-seawater was pumped up from a shallow well of about 5 m in the coastal landfill, and its NaCl concentration was 2.8-
It was 3.2% (average 3.0%).

As shown in the system flow diagram of FIG.
The half seawater is first stored in the raw water tank 9. Then, it is sent to the 5μ double-sided cuno filter 17 by the quantitative pump P,
Rough contaminants are filtered and removed. Then, it passes through ^two hollow fiber filters 13 (Kuraray Co., Ltd., trade name SF filter, SF312, 0.1 μ, 7 m ² ) as a microporous thin film to obtain semi-seawater almost sterilized. This sterilized half seawater is stored in the primary tank 18. The amount of semi-sea water filtration treatment was 4 m ³ / H. In addition, S is a level sensor of the liquid level in the tank, and F is a filter.

Then, the semi-seawater after the filtering process is sent to the electrolysis mechanism 1 by the metering pump P and subjected to the electrolysis process. The half seawater after the electrolysis treatment is stored in the secondary tank 19. The electrolysis area of the electrolysis mechanism 1 is 3 dm ² with one electrolysis module shown in FIG.
Two connected in parallel (total electrode area is 3 × 12 = 36
dm ² ) was used. The conditions of electrolysis are 12 Amp for each electrolysis module (12 Amp x 12 = 144 Amp when all 12 electrolysis modules are used)
5V, the amount of electrolysis processed is 1-2 m ³ / H, and the residual chlorine concentration of electrolytically treated water is between 10 ppm when using two electrolysis modules and 220 ppm when using eight electrolysis modules. Enabled variable settings.

By the way, a large amount of crushed ice is required for the transportation of raw oysters, shrimp, crabs, and fresh fish, but in order to maintain freshness and prevent bacterial contamination in the processing and distribution process, it is used as immersion water or ice. It is believed that what has been shown in each of the above examples makes a very large contribution.

Also, due to changes in eating habits, it is becoming more common for households not to purchase whole fish, but to use fresh fish processed into sashimi (sashimi) and fillets at supermarkets. It is processed in the kitchen attached to each store. However, in recent years, all fishing associations and each prefecture fishing association have developed a centralized processing and distribution system for marine products and the like, and it is assumed that the above-mentioned embodiments make a great contribution to the provision of fresh marine products and other fresh products. Be convinced.

[0068]

[Table 1]

[0069]

[Table 2]

[0070]

[Table 3]

[0071]

[Table 4]

[0072]

The present invention is configured as described above and has the following effects.

The coliforms and general bacteria of seawater or water containing electrolytes such as salt have been reduced or eliminated by electrolysis, and the activities of the coliforms and general bacteria to the fresh food to be immersed are hypochlorous acid and / or It can be suppressed or stopped by sodium hypochlorite. Therefore, it is possible to provide the immersion water for maintaining the freshness of fresh products which can maintain the freshness and is hygienically superior to the conventional one, the manufacturing method thereof, and the manufacturing apparatus thereof.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view illustrating an electrolysis mechanism of an embodiment of an apparatus for producing immersion water for maintaining freshness of fresh products according to the present invention.

FIG. 2 is a system flow chart for explaining the first embodiment of the present invention.

FIG. 3 is a system flow chart illustrating a second embodiment of the present invention.

FIG. 4 is a system flow diagram illustrating a third embodiment of the present invention.

[Explanation of symbols]

 1 Electrolysis mechanism 12 Microporous thin film

Claims (8)

[Claims] 1. Coliform bacteria and general bacteria are reduced by electrolysis of water containing electrolytes such as seawater or salt, and hypochlorite and / or sodium hypochlorite produced by electrolysis are contained. Immersion water for maintaining the freshness of fresh products, characterized by 2. Ice-making water for maintaining the freshness of fresh products, characterized in that the immersion water for maintaining the freshness of fresh products according to claim 1 is used after being frozen. 3. Ice for keeping freshness of the fresh product, characterized in that the immersion water for keeping the freshness of the fresh product according to claim 1 is frozen. 4. Cleaning water for maintaining freshness of fresh products, characterized in that immersion water for maintaining freshness of fresh products according to claim 1 is used for cleaning during processing of fresh products. 5. Freshness characterized by electrolyzing so as to reduce coliform bacteria and general bacteria of water containing an electrolyte such as seawater or salt and to generate hypochlorous acid and / or sodium hypochlorite. A method for producing immersion water for maintaining the freshness of a product. 6. The immersion for keeping freshness of perishables according to claim 5, wherein seawater or water containing an electrolyte such as salt is filtered through a microporous thin film to separate and remove coliform bacteria and general bacteria and pollutants. Water production method. 7. An electrolysis mechanism for reducing coliform bacteria and general bacteria of water containing an electrolyte such as seawater or salt and for producing hypochlorous acid and / or sodium hypochlorite. An apparatus for producing immersion water for maintaining the freshness of fresh products. 8. The freshness-preserving fresh product according to claim 7, comprising a microporous thin film for separating and removing contaminants such as coliforms and general bacteria of water containing electrolytes such as seawater or salt. Immersion water production equipment.