JPH0430854A - Sterilization by ozone liquid - Google Patents

Abstract

PURPOSE:To enable sterilizing of vegetables or the like effectively by adding an organic acid to adjust pH to a set value. CONSTITUTION:For example, acetic acid is added to an ozone liquid as an organic acid to adjust pH to 3.5-4.5. A sticky substance having bacteria attached to vegetables is dissolved in the ozone liquid. This can increase a rate of sterilization up to about 99-99.99%.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to 5 stories of sterilization using ozonated water.

[Conventional technology]

One aspect of the conventional sterilization method using ozonated water will be explained with reference to FIG.

In FIG. 3, objects to be sterilized, such as vegetables and fish, are immersed in cold water 2 in a sterilizing water tank 1, and the temperature of the cold water 2 is set at 0 to 10°C through a cooling coil 3.

The cooled water 2 is sent to the dissolution tank 9 by the circulation pump 7, and the dissolution tank 9 is provided with an aeration pipe 8, and the ozone introducing vibrator 5 is used to raise the ozone concentration to 30. OOOppm gas is supplied at a liquid-gas ratio of 5 to 20 vol/vol.

The capacity (dimensions) of the dissolving tank 9 is determined so that the supplied ozone gas comes into contact with cold water for 5 to 30 seconds after being diffused and mixed with gas and liquid.

The cold water 2 in which ozone has been dissolved is returned to the water tank 1 again.
Sterilize the objects inside.

In order to enhance the sterilization effect, ultrasonic waves are generated from an ultrasonic transducer 10 installed so as to face the object to be sterilized. Ultrasonic frequencies generally range from 19 to 420 kHz.

To prevent this, a gas suction port 11 is placed directly above the water surface around the water tank 1.
The system uses a blower to actively exhaust the air outside the room.

[Problem to be solved by the invention]

In the ozonated water sterilizer shown in FIG. 3, even if vegetables etc. are irradiated with ultrasonic waves in ozonated water, the sterilization rate of bacteria firmly or densely attached to the vegetable surface is about 99%. This is because bacteria that exist in the recesses on the surface of vegetables, etc., or bacteria that protect themselves by releasing adhesive substances such as peptone, remain.

In view of the above-mentioned state of the art, the present invention aims to provide ozonated water that can more effectively sterilize vegetables and the like.

[Means to solve the problem]

The present invention is a sterilization method using ozonated water, which is characterized in that objects to be sterilized are sterilized with ozonated water whose pH has been adjusted to 3.5 to 4.5 by addition of an organic acid.

[Effect]

l) By adding an organic acid to ozonated water, it is possible to promote the dissolution of sticky substances such as peptone that cause bacteria to expel and adhere to vegetable surfaces. Note that excessive addition to a pt of 13.5 or less will damage the vegetables themselves and also cause corrosion of the equipment, so this should be avoided.

2) By adding an organic acid, the solubility of ozone can be increased (up to about 10 times) compared to the case of just water.

〔Example〕

Figure 1 shows the results when cabbage was sterilized by adding acetic acid as an organic acid to ozonated water and adjusting the pH to 4. For comparison, the sterilizing effects of conventional ozone alone, ozone + ultrasound, chlorine, and alcohol are also described.

Adjusting the pH of ozonated water using acetic acid alone is quite effective, but the effect increases significantly when combined with ultrasonic waves.

Furthermore, the influence of pH, in other words, the amount of acetic acid added, is shown in FIG. From FIG. 2, it can be seen that when pu is 4 or less, the bactericidal effect is greatly improved.

〔Effect of the invention〕

1) The sterilization rate can be increased by adding organic acids such as acetic acid to remove or sterilize bacteria that adhere to vegetables that could not be removed or sterilized even by ultrasonic irradiation in ozonated water, and dissolve the sticky substance produced by the adherent bacteria in ozonated water. 99-99% compared to the conventional 90-99%.
It can be increased to 99%.

2) If acetic acid (vinegar) is used as the organic acid, it is inexpensive and there is no problem in terms of food hygiene even if it remains in vegetables.

3) If organic acids are added, the saturation solubility of ozone can be increased to a maximum of 1
Since the increase is approximately 0 times, the amount of unabsorbed ozone gas when the ozone gas is dissolved is reduced, which is effective.

[Brief explanation of the drawing]

FIG. 1 is a chart showing the effect of the present invention, FIG. 2 is a chart showing the pH adjustment effect by acetic acid, and FIG. 3 is a schematic diagram showing a conventional ozone water sterilization device combined with ultrasonic waves. In Figure 3, 1: Sterilizing water tank, 2: Cold water, 3: Cooling pipe, 4: Filter, 5 Niosin introduction pipe, 6: Cold water inlet, 7: Circulation pump, 8: Diffusion pipe, 9: Dissolution tank, 1
0: Ultrasonic vibrator, 11: Gas suction port.

Claims (1)

[Claims] A sterilization method using ozonated water, which comprises sterilizing objects to be sterilized with ozonated water whose pH has been adjusted to 3.5 to 4.5 by adding an organic acid.