JPH01225441A - Sterilization of vegetable and fruit with ozone water and apparatus therefor - Google Patents

Abstract

PURPOSE:To have high sterilization and cleaning effect on vegetables and fruits in a short operation time, by introducing into an ozone solution immersed with said vegetables and fruits an ozone gas-suspended high-concentration ozone solution produced by introducing ozone gas via fine holes into an ozone solution. CONSTITUTION:The water in a vegetable-and-fruit immersion tank 2 is passed through an ozone dissolver 3 using a pump 28, while an ozone gas from an ozone generator 38 is fed via a porous hollow pie 8 into a pressurized ozone chamber 41. The fine ozone bubbles thus formed in a dissolving chamber 43 produces an ozone gas-suspended high-concentration ozone water, which is then released via a feed pipe 14 through blowout holes 34 into the tank 2.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a method and apparatus for sterilizing fruits and vegetables such as vegetables and fruits. In particular, the present invention relates to a method and an apparatus for sterilizing common bacteria, Escherichia coli, that adhere to the leaves, stems, roots, pericarp, and cut surfaces of fruits and vegetables after harvesting.

(b) Conventional technology Traditionally, fruits and vegetables are sterilized after harvest by immersing them in an aqueous solution of a disinfectant such as hypochlorous acid, sodium hypochlorite, hydrogen peroxide, or bleaching powder, or by using ozone gas. ★
This is carried out by a method in which fruits and vegetables are treated by direct aeration into a fruit soaking tank, or a method in which fruits and vegetables are processed in a fruit and vegetable soaking tank filled with ozone gas mixed water, which is a mixture of water and ozone gas, using an ejector.

In addition, a method has been proposed in which food is thoroughly immersed in water and then brought into contact with low-concentration ozonated water (Japanese Unexamined Patent Publication No. 1983-1992).
1,416,178).

(c) Problems to be solved by the invention However, in sterilizing these fruits and vegetables, the method of immersing them in an aqueous solution of a sterilizing agent such as hypochlorous acid or bleaching powder requires, for example, several hundred pp. - Due to the use of highly concentrated chemicals, the chemicals adhere to the surface of the soaked fruits and vegetables, and if left untreated, the quality of the fruits and vegetables deteriorates, or the impact on the human body cannot be ignored, so after soaking the fruits and vegetables,
Requires rewashing and rinsing with large amounts of water.

On the other hand, ozone sterilization is superior because ozone decomposes in a relatively short period of time even if it adheres, and no residue remains.
Due to the low solubility of ozone in water, for example, the direct aeration method of ozone gas in a fruit and vegetable soaking tank or the mixing method of ozone gas and water using an ejector have poor dissolution efficiency of ozone gas in water, making it difficult to sterilize fruits and vegetables. This is a problem because it takes a long time and costs a lot of money.

An object of the present invention is to solve problems related to the efficiency of dissolving ozone gas into water in conventional methods and devices for sterilizing fruits and vegetables using ozonated water.

(d) Means for Solving the Problems The object of the present invention is to provide a method for sterilizing fruits and vegetables using ozonated water, which sterilizes fruits and vegetables by dissolving ozone gas in water with high dissolution efficiency.

That is, the present invention provides a method for sterilizing fruits and vegetables with ozonated water, in which the fruits and vegetables are immersed in ozonated water.
The ozone solution is introduced through a hole with a pore size of 10 microns or less to generate a highly concentrated ozone solution in which ozone gas is suspended, and the highly concentrated ozone solution containing the ozone gas suspended in the ozone solution is introduced into the ozone solution in which fruits and vegetables are immersed. The present invention relates to a method for sterilizing fruits and vegetables using an ozone solution, which is characterized in that the ozone solution is used to sterilize fruits and vegetables by introducing an ozone solution into the ozone solution. an ozone dissolution tank that is partitioned into an ozone chamber having an ozone solution inlet and an ozone dissolution chamber having an ozone solution inlet and a high concentration ozone solution outlet for suspending ozone gas;
Fruit and vegetable immersion comprising: an ozone solution outflow section communicating with the ozone solution introduction section of the ozone dissolution tank; and a high concentration ozone solution introduction section for suspending ozone gas that communicates with the high concentration ozone solution outflow section for suspending ozone gas in the ozone dissolution tank. It is characterized by comprising a tank, and a high concentration ozone solution blowing pipe for ozone gas suspension, which is arranged in the fruit and vegetable dipping tank and has a plurality of openings connected to the high concentration ozone solution introduction part for ozone gas suspension. There is a sterilizer for fruit and vegetables.

In the present invention, fruits and vegetables refer to some or all of the fruits and vegetables that have been harvested.

In the present invention, in order to enhance the sterilization effect on fruits and vegetables, it is preferable to soak the whole fruits and vegetables in ozonated water and wash them.
In the present invention, the fruits and vegetables to be sterilized are immersed in an ozone solution such that they are exposed to a flow of relatively highly concentrated ozone solution that suspends ozone gas.

In the present invention, pressurized ozone gas, for example pressurized ozone gas containing unconverted oxygen, is made into fine bubbles and brought into contact with water in order to dissolve ozone in water in a short time. In this case, in the present invention, in order to form ozone gas into fine bubbles in water, ozone gas is passed through pores with a pore size of 10 microns or less, for example, through micropores of a porous isolation member with a pore size of 10 microns or less. , dissolved in water. In this case, it is sufficient that the micropores used have an average diameter of about 0.1 to 10 microns, but they are formed with an average diameter of 3 to 5 microns, and the pores are relatively uniform. The method described above is preferable because it can dissolve a large amount of ozone extremely efficiently.

Therefore, in the present invention, the porous isolation member having fine pores is a material in which many fine pores with a pore diameter of 10 microns or less are formed, and has excellent water resistance and corrosion resistance.
Any material can be used as long as it has the mechanical strength to withstand the gas pressure of pressurized ozone. Such materials include, for example, porous materials such as fine-mesh porous glass and porous ceramics. In particular, materials called siliceous porous glasses, that is, S, P, and G, have water resistance. , is an excellent material with corrosion resistance and uniform micropore size, and is preferred because it is easily available.

In the present invention, ozone gas is dissolved in water through pores with a pore size of 10 microns or less to generate a relatively highly concentrated ozone solution. Also, the state of contact between the generated ozone solution and ozone gas is maintained for a predetermined period of time. Therefore, in the present invention, ozone gas is
Even after passing through pores of 0 micron or less, they remain suspended in the relatively highly concentrated ozone solution in the form of fine bubbles.

In addition, in the present invention, the highly concentrated ozone solution in which this ozone gas is suspended is introduced into the ozone solution in which the fruits and vegetables are immersed, and the concentration of the ozone solution in which the fruits and vegetables are immersed is increased to a supersaturated state, and fine ozone gas is , for example, will disperse ozone gas containing unconverted oxygen.

In the present invention, in order to reduce the consumption of ozone and increase the concentration of the ozone solution over a predetermined period of time, it is preferable to contact the ozone solution that is consumed during the fruit and vegetable soaking step and which still contains ozone with pressurized ozone.

In the present invention, in order to enhance the dissolution of ozone in the ozone gas into the ozone solution, the ozone solution with which the ozone gas comes into contact is preferably kept at a low temperature, for example, at a temperature of 0°C to 10°C.

In the present invention, in order to keep the ozone concentration in the ozone solution in which the fruits and vegetables are immersed constant, a part of the ozone solution in which the fruits and vegetables are immersed is extracted from the vegetable and fruit soaking tank and brought into contact with pressurized ozone gas, and the ozone solution is removed. Preferably, a highly concentrated ozone solution in which the pressurized ozone gas is dissolved and suspended is continuously introduced into the soaking point of the fruits and vegetables.

In the apparatus of the present invention, the fruit and vegetable soaking tank is connected to an ozone dissolution tank that includes at least a pressurized ozone chamber and an ozone dissolution chamber connected to an ozone supply source, and the pressurized ozone chamber and the ozone dissolution chamber are provided with a porous It is partitioned with a quality isolation member to allow ozone gas to pass through.

The inlet of the ozone dissolution chamber is connected to the outlet of the fruit and vegetable soaking tank so that the ozone gas in the pressurized ozone chamber is dissolved in the water in the fruit and vegetable soaking tank. A single circulation path is formed in communication with the inlet of the tank.

In this case, the porous isolation member can be formed into various shapes such as a plate shape, a box shape, or a hollow tube shape.

When the pressurized ozone chamber is formed into a cylindrical shape using the porous isolation member, it is preferable to provide it inside the ozone dissolution chamber because the contact area between ozone gas and water becomes large. When the porous isolation member is formed into a cylindrical shape, it is preferably installed in a pressurized ozone chamber. In either case, in order to uniformly increase the dissolved concentration of ozone in water, It is preferable to constantly circulate the water.

In addition, in the present invention, when a pressurized ozone chamber or an ozone dissolution chamber is configured with a porous hollow tube, the porous hollow tube is
Not only one but a plurality of them may be provided in the ozone dissolution tank.

In the present invention, in order to suspend ozone gas in the ozone high concentration solution for a long time and measure the contact between the ozone gas and the ozone high concentration solution, the outlet side of the ozone dissolution chamber is preferably formed into a pipe. .

In the present invention, the inside of the fruit and vegetable soaking tank is, for example, 0 to 10
Since the freshness of fruits and vegetables can be maintained by keeping the vegetables at a low temperature of .degree. C., a cooler can be provided in the soaking tank.

(e) Effect In the present invention, pressurized ozone gas containing more than a saturated amount of ozone is brought into contact with an ozone solution at a low temperature of, for example, 0°C to 10°C, through fine pores with a diameter of 10 microns or less. A large amount of ozone gas bubbles are generated in the low-temperature ozone solution, which dissolves a large amount of ozone and creates a highly concentrated ozone solution in which the remaining ozone gas that is not dissolved is suspended in the form of fine bubbles. generated.

In the present invention, fruits and vegetables are immersed so as to be exposed to this highly concentrated ozone solution containing ozone gas suspension, so that the fruits and vegetables are
The bacteria such as E. coli attached to the surface of the soaked fruits and vegetables are easily sterilized in a short time because they come into contact not only with an ozone solution with a high ozone concentration but also with fine ozone bubbles. become.

In the apparatus of the present invention, the pressurized ozone chamber and the ozone dissolution chamber are communicated with each other through the fine holes of the porous isolation member, so that the dissolution of ozone is promoted in the ozone dissolution chamber, and the ozone dissolution chamber is A large amount of highly concentrated ozone water is obtained, and fine ozone gas bubbles are suspended. Such a high concentration ozone solution containing ozone gas suspended is blown out from the high concentration ozone solution blowing hole containing ozone gas suspended in the fruit and vegetable soaking tank and comes into contact with the fruits and vegetables, so that the fruits and vegetables come into contact with the highly concentrated ozone solution. At the same time, since it also comes into contact with suspended ozone gas, the surface of fruits and vegetables can be sterilized efficiently and easily. Moreover, this high-concentration ozone solution containing ozone gas suspension mixes with the surrounding liquid after being ejected, increasing the ozone concentration of the surrounding liquid to a supersaturated concentration. can be efficiently sterilized.

In addition, the ozonated water in this fruit and vegetable soaking tank is disturbed by a jet of a high concentration ozone solution containing ozone gas suspension that is ejected, and is circulated between the fruit and vegetable soaking tank and the ozone dissolution chamber to constantly maintain the quality of the fruit and vegetables. Bringing a highly concentrated ozone solution containing ozone gas into contact with the surface.

Therefore, according to the present invention, even if ozone is used, the surfaces of fruits and vegetables can be sterilized in a short time, so that the fruits and vegetables after sterilization will not undergo discoloration or deterioration due to oxidation.

(F) EXAMPLES Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings, but the present invention is not limited in any way by the following explanations and examples.

FIG. 1 is a schematic explanatory diagram of one embodiment of the present invention, FIG. 2 is a schematic partial side sectional view of an ozone dissolving tank in another embodiment of the present invention, and FIG. FIG. 2 is a schematic partial side sectional view of an ozone dissolving tank in still another embodiment of the present invention.

In FIG. 1, an ozone sterilization apparatus 1 for fruits and vegetables includes a fruit and vegetable soaking tank 2 and an ozone dissolving tank 3.

The ozone dissolving tank 3 is constructed by inserting a porous hollow tube 8 into a tubular body 7 in which a pressurized ozone gas inlet 4 and a drain 5 are formed on a side wall 6. 10, by placing the O-ring 11 on the protrusion of the first fixed flange pipe 12 and deforming it,
In this example, both ends 9 of the tubular body 7 are fixed.
and 10, a water suction conduit 13 and a supply conduit 14 are connected.

The connection structures of the conduits 13 and 14 to the tubular body 7 are the same, so for convenience of explanation, only the connection structure on the water absorption conduit 13 side is shown broken in FIG. 1.

A second fixed flange tube 16 is pushed inside the first fixed flange tube 12 which is screwed into the inner thread 15 of the end 9 of the tubular body 7 . The second fixed flange pipe 1
The extension portion 17 of No. 2 connects the flange portion 22 of the presser tube 21, the extension portion 20 of which is inserted into the center hole 19 of the No. 1 bag nut 18 which is screwed onto the bag nut 18 on the outside, to the flange portion 22 of the retainer tube 21.
8 is screwed onto the outside of the first fixed flange tube 12 and pushed in, thereby deforming the O-rings 11 and 11' and fixing the porous hollow tube 8 airtightly.

At the end of the extension part 20 of the holding pipe 21, the end 2 of the water suction pipe is attached.
3 is fixed by a fastener 24.

A water supply pipe 25 is connected to the water suction pipe 13 via a valve 26, and one end is immersed into the fruit and vegetable soaking tank 2 via a valve 27 and a pump 28, and a strainer 29 is attached thereto.

In order to increase the dissolved concentration of ozone in the water supply water, the water supply pipe 13 is provided with a pipe near the connection side to the ozone dissolution tank 3.
A cooler 30 for adjusting water temperature is provided.

On the other hand, the supply conduit 14 is connected to an extension 32 of the presser tube 31 on one side, and the other end 33 is opened to form a blowout section 35 with a plurality of blowout holes 34. .

Further, an ozone gas introduction pipe 36 connected to the ozone gas introduction port 4 is provided with a pulp 37 and an ozone generator 38, and its end is opened to an O2 gas cylinder 39 or the atmosphere to form an intake port 40. .

The pressure of the ozone gas supplied to the pressurized ozone chamber 41 of the ozone dissolution tank 3 is measured by a pressure gauge 42 attached to the ozone gas introduction pipe 36, and the water pressure of the ozone dissolution chamber 43 in the porous hollow tube 8 is , can be determined by the pressure gauge 44 attached to the water suction conduit 13.

In this example, the material of the porous hollow tube 8 used in the ozone dissolution tank 3 is porous glass. This porous glass was synthesized by Tadao Nakajima, Shimizu Technical High School, and Mikio Kono of the Miyazaki Industrial Research Institute, using volcanic ash shirasu, which is abundantly found in the Pobonyo belt, as the main raw material, and adding lime and boric acid to it. Cd
-B2 island-5iO, -AI! ,0. Heat treatment of glass
By acid treatment, a porous glass with extremely precisely controlled micropores is generated, and a patent application has been filed for its manufacturing method, which is disclosed in Japanese Patent Application Laid-Open No. 140334/1982.
Commonly known as S, P, and G.

(Shirasu Porous Glass).

It is hard and has heat and water resistance, and plays an extremely important role in the present invention.

In this example, the ozone dissolving tank 3 has a wall thickness of 5 cm and an inner diameter of 2 cm.
It is made of acrylic resin and has a total length of 0m+* and a total length of 200mm, and the porous hollow tube 8 provided therein is the same as the above-mentioned S, P, and G.

It has a wall thickness of around 11, and many pores of about 3 to 5 microns are formed in it (porosity of 50% or more).
, an outer diameter of 10III and a total of 1% 2OOLLII are used.

In this example, the fruit and vegetable soaking tank 2 has a capacity of 2001. While the ozone generator 38 introduces ozone gas in the amount of 11/min into the pressurized ozone chamber 41, the supply pump 28 introduces the ozone water in the fruit and vegetable soaking tank 2 into the pressurized ozone chamber 41.
It is supplied to the ozone dissolution chamber 43 at a flow rate of 100 min. In the ozone dissolution chamber 43, for example, a highly concentrated ozone solution in which ozone gas containing unconverted oxygen is suspended and ozone is dissolved is produced, and highly concentrated ozone water in which this ozone gas is suspended is passed through the supply conduit 14. , is supplied to the fruit and vegetable soaking tank 2.

Further, the ozonated water 45 in the fruit and vegetable soaking tank 2 is supplied to the ozone dissolution chamber 43 at a rate of 101/min via the strainer 29 and the water suction conduit 13 by the water suction (circulation) pump 28, and is circulated to the fruit and vegetable soaking tank 2 again. .

Since this example is configured as described above, water is introduced into the fruit and vegetable soaking tank 2 in advance, and the water is passed into the ozone dissolving tank 3 by the supply pump 28. Ozone gas generated by an ozone generator 38 is sent into the porous hollow tube 8 at a predetermined pressure to a pressurized ozone chamber 41 formed outside the porous hollow tube 8. The ozone gas sent in this way contains unconverted oxygen, and the entire amount is supplied into the ozone dissolution chamber 43 through the micropores of the porous hollow tube 8, forming fine bubbles of ozone gas in the water. do. Part of the fine ozone gas bubbles thus formed in the dissolution chamber 43 is dissolved in the pressurized water supplied into the ozone dissolution chamber, and the remainder is dispersed in a suspended state.

The highly concentrated ozone water in which ozone gas is suspended in the ozone dissolving chamber 43 dissolves a large amount of ozone and also has a large amount of ozone gas suspended therein. This dissolved high-concentration ozone water flows out from the ozone dissolution chamber 43 into the supply conduit 14 and is then discharged from the supply conduit 14 into the fruit and vegetable soaking tank 2 through the plurality of blow-off holes 34 . In this way, highly concentrated ozonated water in which ozone gas is dissolved and suspended is released, and the ozonated water in the fruit and vegetable soaking tank 2 reaches a supersaturated state in ozone concentration and becomes a state in which fine ozone gas is dispersed. .

When fruits and vegetables are immersed in ozonated water 45 that dissolves a large amount of ozone and suspends a large amount of excess ozone gas, bacteria such as E. coli attached to the surface of the fruits and vegetables are easily sterilized by the ozonated water 45. be able to.

Furthermore, the ozonated water 45 in this fruit and vegetable soaking tank 2 passes through a strainer 29 and a water suction pipe 25, and then passes through a water suction (circulation) pump 2.
8, it is returned to the ozone dissolution chamber 43 again, where it is again brought into contact with pressurized ozone gas to replenish ozone,
It circulates through the supply conduit 14 to the fruit and vegetable soaking tank 2 .

In this example, a water temperature adjustment cooler 30 is installed in the water suction pipe 13.
is installed, which not only increases the solubility of ozone but also adjusts the temperature of the ozonated water flowing through the supply conduit 14 to adjust the temperature of the ozonated water 45 in the fruit and vegetable soaking tank 2 to a predetermined range. can do. In addition, in addition to the cooler 30 for adjusting the water temperature of the supply conduit 14, for example, a water temperature adjustment device is provided in the fruit and vegetable soaking tank 2 to adjust the temperature of the ozonated water 45 in the fruit and vegetable soaking tank 2 within a predetermined range. You can also.

When the water level in the fruit and vegetable soaking tank 2 drops from a predetermined level due to evaporation, etc., the pump 46 is activated to drain the water supply pipe 2.
Fresh water can be supplied from 5 via valve 26.

In the example shown in FIG. 2, in the ozone dissolution tank 3,
A plurality of porous hollow tubes 8 are attached, and by providing a plurality of porous hollow tubes in this way, a plurality of ozone dissolution chambers can be provided in the pressurized ozone chamber. When the ozone dissolution chamber is provided in the pressurized ozone chamber in this way, the contact area for dissolution is further increased, and the efficiency of ozone dissolution can be increased.

In this example, the ozone dissolution tank 3 is provided with a plurality of porous hollow tubes 8, each of which has a fixed tube plate 4 of the tubular body 7.
7 through the O-ring 11. In this case, the O-ring 11 is
It is deformed by screwing the fixed flange pipe 49 through the porous hollow pipe 8, and plays the role of closely contacting the wall of the porous hollow pipe 8 and holding it. A flange portion 52 of a cylindrical end plate 51 is bolted to a flange portion 50 of the fixed tube plate 47, and an end portion 54 of a water suction conduit 13 is connected and fixed to a central opening 53 thereof.

In the example shown in FIGS. 1 and 2, water is introduced into the ozone dissolution chamber 43 under pressure of about 1 kg/c-''. 4
0, oxygen or dry air is supplied to the ozone generator 38.
approximately 1 to 1.5 k by the ozone generator 38.
g/am'' pressurized ozone gas is fed through the ozone gas inlet pipe 36 to the pressurized ozone chamber 41 outside the porous hollow tube 8. Pressurized ozonated water containing air bubbles and dissolving ozone at a high concentration can be supplied to the fruit and vegetable soaking tank 2 through the supply conduit 14.

In the example shown in FIG. 3, the end of the tubular body 7 is screwed to the end of the first fixed flange pipe 12 (threads are not shown), as in FIG. ), this is an example in which a pressurized ozone chamber 41 is provided in a porous hollow tube 8, and in this case, a desired number of porous hollow tubes 8 are fixed in the ozone dissolution tank 3, so that the It is possible to form an ozone dissolution tank having a desired number of ozone chambers within the pressurized ozone dissolution chamber.

In this example, one end 55 of the porous hollow tube 8 is connected to the O-ring 11 between the first fixed flange tube 12 and the second fixed flange tube 16, similar to the example of FIG. The chamber 5 is fixed by deforming the porous tube 8 and surrounds the end 55 of the porous hollow tube 8.
6, the O-ring 11' between the presser cover member 57 and the second fixed flange pipe is attached together with the O-ring 11, and the cap nut 58 is attached to the first fixed flange pipe 1.
2 (screw threads are not shown), and is pressed and deformed by the presser cover member 57.

One side wall 7 of the ozone dissolution tank 3 is provided with an inlet 59 connected to the water suction conduit 13, and the other side is provided with an outlet 60 connected to the supply conduit 14.

When sending ozone gas to the porous hollow tube 8, oxygen or dry air is supplied to the ozone generator 38 from the 0□ gas cylinder 39 or the intake port 40, and the ozone gas generated by the ozone generator 38 is fed to the pulp 37. , about 1 to 1.5 kg
/ e＋＊' G pressure! On the other hand, the water or ozone water 45 in the fruit and vegetable soaking tank 2 is introduced into the ozone chamber 62 from the ozone gas introduction pipe 36.
1 at a pressure of about 1 kg/am'G. In the ozone dissolution chamber 61, microbubbles are generated in the supplied water or ozone water through the porous partition wall, and the ozone gas in these microbubbles is dispersed in the supplied water or ozone water to suspend ozone gas. Highly concentrated ozonated water is formed which becomes cloudy. The highly concentrated ozonated water in which the ozone gas thus formed is suspended in the fruit and vegetable soaking tank 2 by the supply conduit 14 through the plurality of blow-off holes 34, similarly to the example shown in FIG.

The results of an ozone dissolution test conducted using the apparatus shown in FIG. 1 and a conventional aeration cylinder type apparatus are shown below as a comparative example.

[Comparative example]

At a room temperature of 16°C to 21°C and a temperature of 50%, the fruit and vegetable soaking tank 2 is filled with tap water 501 with a water temperature of 5°C, and the strainer 2
9. Through the water suction pipe 13, operate the circulation pump 28 to remove the SPG pipe (pore diameter: 4.5 microns,
Porosity: 50%) Water flow rate 101/min inside of 8, 1k
Water is passed under pressure at a pressure of g/c+*”G.

On the other hand, after pressurized ozone gas is injected from the outside at a flow rate of IN1/min and a pressure of 1 kg/am2G or more, it is supplied from the supply conduit 14 through the blow-off hole 34 to the fruit and vegetable soaking tank 2, and the change in ozone concentration when circulated is measured. Examined.

On the other hand, the aeration cylinder (pore diameter 4.5 microns, porosity 50
%) was directly submerged in cold water (5° C., 501) in the fruit and vegetable soaking tank 2, and the change in ozone concentration was also investigated when ozone gas was aerated underwater under the same conditions as above. These results are shown in the graph of FIG.

In this figure, the horizontal axis of the graph shows the operating time (minutes), and the vertical axis shows the dissolved ozone concentration (pl). Further, the solid line is a curve showing the change in dissolved ozone concentration with respect to the operating time of ozonated water produced by the method according to the present invention, and the dotted line is a curve showing the change in dissolved ozone concentration with respect to the operating time of ozonated water produced by direct aeration in the aquarium using the aeration pipe. This is a curve showing changes in ozone concentration.

As is clear from the figure, it was confirmed that ozonated water with a higher dissolved ozone concentration could be obtained in a shorter operating time than with the conventional aeration cylinder system, and that a remarkable ozone dissolution effect could be obtained.

Examples are shown below in which tests were conducted on the effectiveness of disinfecting and cleaning E. coli, a common bacteria that adheres to fruits and vegetables, according to the present invention.

Using the apparatus shown in the example shown in the first diagram above, pressurized ozone gas was continuously injected and dissolved into cold water (5°C) filled in Fruit and Vegetable Soaking (2001) through an SPG pipe to generate ozonated water. Table 1 shows the results of finely cut vegetables (cabbage, Chinese cabbage, lettuce) placed in a soaking tank, samples taken every hour while being washed, and the number of bacteria measured. The results of immersing and washing the same type and amount of vegetables in ℃) and analyzing them at the same time are also shown.

Table 1 Time (minutes) Number of bacteria/gull! Cold water Ozonated water 5 1.9X10' 810 3
,Ox 10' (27) 9 (0)20
2.9x 10' 230 3.
2X 10' (79) O(0)60
3, OX 10' 0 [Note: The number in parentheses indicates the number of E. coli/ml.

As described above, it was found that sterilization was almost completely completed several minutes after immersion cleaning, confirming the excellent effects of the present invention.

(G) Effects of the Invention The present invention provides a highly concentrated ozone solution containing an ozone gas suspension by bringing pressurized ozone into contact with an ozone solution at a low temperature of, for example, 0°C to 10°C through fine pores with a diameter of 10 microns or less. Even though ozone has a self-decomposition property with a half-life of 10 minutes, ozone is constantly replenished from the surroundings, and the concentration of the ozone solution in the fruit and vegetable soaking tank reaches a concentration higher than the supersaturation concentration. It will be enhanced.

Therefore, according to the present invention, compared to conventional methods and devices, for example, ozonated water containing a large amount of ozone per unit amount in gaseous and solution form can be used to sterilize greens and fruits. Compared to conventional methods and devices, a high sterilizing cleaning effect can be achieved in a short operating time, and the amount of sterilizing fruits and vegetables per unit time can be increased.

Further, the present invention provides an ozone dissolution tank that is divided into a pressurized ozone chamber and an ozone dissolution chamber by a porous partition having fine pores with a pore diameter of 10 microns or less, and ozone gas is removed to zero.
A highly concentrated ozone solution containing ozone suspension is produced by contacting with an ozone solution at a low temperature of ℃ to 10℃, and the ozone concentration of the ozone solution in the fruit and vegetable soaking tank is reduced to a supersaturation concentration by this highly concentrated ozone solution containing ozone suspension. Because it is sterilized by
Compared to conventional ozonated water production equipment, this device has a simple structure, is easy to operate, and can sterilize large quantities of fruits and vegetables at low cost.

[Brief explanation of the drawing]

FIG. 1 is a schematic explanatory diagram of one embodiment of the present invention, FIG. 2 is a schematic partial side sectional view of an ozone dissolving section in another embodiment of the present invention, and FIG. The figure is a schematic partial side sectional view of an ozone dissolving section in another embodiment of the present invention. Figure 4 is a graph showing the results of a comparative example of ozone dissolution using the present invention and the prior art.6 Figures 1 to 3
Regarding the symbols in the figure, 1 is an ozone sterilizer, 2 is a fruit and vegetable soaking tank, 3 is an ozone dissolution tank, 4 is a pressurized ozone gas inlet, 5 is a drain, 6 is a side wall, 7 is a tubular body, and 8 is a porous 9 and 10 are both ends of the cylinder, 11 and 11' are O-rings, 12 is a first fixed flange pipe, 13 is a water suction conduit, 14 is a supply conduit, 15 is a thread, and 16 is a third a second fixed flange pipe; 17 is an extension of the first fixed flange pipe;
8 is a cap nut, 19 is a central hole, 20 is an extension part, 21 is a holding pipe, 22 is a flange part, 23 is an end of a water suction pipe, 24
is a fastener, 25 is a water supply pipe, 26 is a valve, 27 is a valve,
28 is a pump, 29 is a strainer, 30 is a cooler for adjusting water temperature, 31 is a holding pipe, 32 is an extension part, 33 is the other end, 3
4 is a blowout hole, 35 is a blowout part, 36 is an ozone gas introduction pipe,
37 is a valve, 38 is an ozone generator, 39 is 0! Gas cylinder, 40 is an intake port, 41 is a pressurized ozone chamber, 42 is a pressure gauge, 43 is an ozone dissolution chamber, 44 is a pressure gauge, 45 is ozonated water, 46 is a pump, 47 is a fixed tube plate, 48 is a screw hole, 49 is a fixed flange pipe, 50 is a flange portion of a fixed tube plate, 51 is a cylindrical end plate, 52 is a flange portion of a cylindrical end plate, 5
3 is a central opening, 54 is an end of a water absorption conduit, 55 is an end of a porous hollow tube, 56 is a chamber surrounding the end, 57 is a holding lid member, 58 is a cap nut, 59 is an inlet, 60 is the outlet, 61
is an ozone dissolution chamber, and 62 is a pressurized ozone chamber. In FIG. 4, the solid line is a curve showing the change in dissolved ozone concentration with respect to the operating time of ozonated water produced by the method according to the present invention, and the dotted line is a curve showing the change in dissolved ozone concentration with respect to the operating time of ozonated water produced by the method according to the present invention, and the dotted line is a curve showing the change in dissolved ozone concentration with respect to the operating time of ozonated water produced by the method according to the present invention. It is a curve showing changes in dissolved ozone concentration with respect to time.

Claims (2)

[Claims] (1) In a method of sterilizing fruits and vegetables with ozonated water, in which fruits and vegetables are immersed in ozonated water, ozone gas is introduced into the ozone solution through holes with a diameter of 10 microns or less to generate a highly concentrated ozone solution in which ozone gas is suspended. A method for sterilizing fruits and vegetables using an ozone solution, which is characterized in that the fruits and vegetables are sterilized by introducing this highly concentrated ozone solution containing ozone gas into the ozone solution in which the fruits and vegetables are immersed. (2) An ozone chamber having a connection part for connecting an ozone supply source, an ozone dissolution chamber having an ozone solution introduction part and a highly concentrated ozone solution outflow part for suspending ozone gas, using a porous partition wall with a pore diameter of 10 microns or less. an ozone solution outflow section that communicates with the ozone solution introduction section of the ozone dissolution tank and an ozone gas suspension section that communicates with the high concentration ozone solution outflow section that suspends ozone gas in the ozone dissolution tank. a high concentration ozone gas suspension having a plurality of openings arranged in the fruit and vegetable dipping tank and connected to the high concentration ozone solution introduction section for the ozone gas suspension; A fruit and vegetable sterilizer characterized by comprising an ozone solution blowing pipe.