JPH10236444A - Method for sterilizing plastic container for beverage - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable sterilization simply and efficiently to secure safety of beverage without losing taste of the beverage to be filled after sterilization by bringing heated chlorinated sodium hydroxide into contact with inner and outer walls of a plastic container an washing in water. SOLUTION: The sterilization method comprises steps of bringing chlorinated sodium hydroxide heated to 30 deg.C or higher into contact with inner and outer walls of a container to sterilize the inner and outer walls, and then washing the chlorinated sodium hydroxide on the inner and outer walls of the container in water. Contact of the chlorinated sodium hydroxide with the container is performed by spraying toward the inner and outer walls of the container, injecting a full amount into the container, soaking the container and dropping down on the outer wall of the container. Chlorinated sodium hydroxide with hypochlorous acid having a concentration of 0.1W/V% or higher added to sodium hydride having a concentration of 0.5W/V% or higher at a mixture ratio in a range of 5W/V% to 30W/V% is used.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for sterilizing beverage containers, particularly plastic containers.

[0002]

2. Description of the Related Art Conventionally, plastic containers such as polyethylene terephthalate containers (PET containers) used for filling beverages are provided with a disinfectant such as hydrogen peroxide solution on the inner wall of the container before the beverages are filled. After spraying the outer wall and the like, a sterilizing process of drying the sterilizing agent with hot air is performed. However, according to this method, the bactericide remains on the inner wall of the container, which impairs the flavor of the packed beverage, and has become a problem particularly in the case of tea beverages or drinking water having a subtle flavor. In addition, there is a problem that the residual bactericide is harmful because it is taken together with the beverage.

[0003] In order to solve such a problem,
Various proposals have been made. For example, JP-A-60-99
Japanese Patent Publication No. 828 discloses a container sterilizer for injecting a sterilizing solution (hydrogen peroxide solution) and then injecting a cleaning solution to remove the sterilizing solution.
Japanese Unexamined Patent Publication (Kokai) No. 63-138931 discloses that a bactericide (hydrogen peroxide solution or the like) is sprayed on a container and then hot air is blown on the container to dry the bactericide. A method for washing and removing is described. However, these methods have a problem that the disinfectant cannot be completely removed. Further, there is a problem that the process is complicated, the equipment becomes enormous, and a required time is required. Further, Japanese Patent Application Laid-Open No. Hei 3-231684 describes a method in which the inner wall of a plastic bottle is heated to a sterilizing temperature by hot water, the outer wall is heated, and the bottle is kept at the sterilizing temperature for a predetermined time to sterilize the bottle. . However, this method has a problem that it can only be used for heat-resistant plastic bottles because of the upper limit of the heat-resistant temperature depending on the material of the plastic bottle.

Therefore, complete sterilization can be performed, and it can be applied to plastic containers of any material. More specifically, sterilization can be performed within the heat-resistant temperature range of plastic bottles that are generally widely used, and can be performed easily. Intensive research has been conducted on a sterilization method for plastic containers for beverages, which can be performed in a simple process, does not leave the disinfectant on the inner wall of the container, and has no effect on beverages packed after sterilization. Against this background, microbiological verification of the results of cleaning the pipes of beverage manufacturing plants revealed that data suggesting that using chlorinated caustic soda as a detergent also has a sterilizing effect. Obtained. In addition, the cleaning of the pipe is to chemically solubilize or remove the adhered residue derived from the fluid flowing in the pipe, or to physically remove and discharge the deposited residue by the flow of the cleaning fluid. It does not mean. Until now, chlorinated caustic soda has been used as a detergent, but it has never been used as a bactericide, and even its bactericidal spectrum has not been revealed. Therefore, based on the existence of the data, we examined the possibility of using chlorinated caustic soda as a disinfectant, and also examined the possibility of disinfecting plastic containers for beverages. The present invention has been completed by solving the problem of residual bacteria and finding an effective and appropriate method of using a disinfectant (concentration, temperature, application time, etc.).

[0005]

DISCLOSURE OF THE INVENTION The present invention provides a plastic container for beverages without any germicide remaining on the inner and outer walls of the container, and is efficiently and completely completed by a simple process and apparatus irrespective of the material of the container. It is an object of the present invention to provide a sterilization method capable of performing sterilization without affecting the beverage packed after sterilization.

[0006]

SUMMARY OF THE INVENTION According to the present invention, after a heated chlorinated caustic soda having a sterilizing effect is brought into contact with the inner and outer walls of a container, the inner and outer walls of the container are similarly washed with water having a high washing effect. It has been made based on the finding that the above-mentioned problem can be solved by doing so. That is, the present invention is to provide a method of sterilizing a plastic container for beverages, which comprises combining heated chlorinated caustic soda having a high sterilizing effect, and water having a high cleaning effect. Is to contact a heated chlorinated caustic soda to an inner wall and an outer wall of a beverage plastic container, and then to wash and sterilize with water.

[0007]

The inner wall and outer wall of the container are first sterilized by contacting the container with heated chlorinated caustic soda. The contact of the chlorinated caustic soda to the container is performed by spraying on the inner and outer walls of the container, filling the inside of the container with the full amount, immersing the container, and dropping on the outer wall of the container. The sterilization method of the present invention is to sterilize the inner and outer walls by contacting a heated chlorinated caustic soda to the inner and outer walls of the beverage plastic container,
The gist is that the chlorinated caustic soda on the inner and outer walls of the container is washed away with water. Further, the present invention can be similarly applied to not only the container but also a cap which is an accessory of the container.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The chlorinated caustic soda used in the present invention is obtained by adding hypochlorous acid to an aqueous solution of sodium hydroxide. / V% to 30 W / V% is used. In the present invention, chlorinated caustic soda is
As a concentration of sodium hydroxide, 0.5 W / V% or more,
Preferably, one having a concentration in the range of 2 W / V% to 6 W / V% is used. Hypochlorous acid has a concentration of 0.1 W / V
% Or more are used. If the concentration of sodium hydroxide in the chlorinated caustic soda is lower than 0.5 W / V%, the bactericidal effect may be insufficient, and if the concentration is higher than 8 W / V%, the safety or workability in the handling thereof. It is inconvenient from the point of view.

[0009] Further, the bactericidal effect of chlorinated caustic soda is significantly improved by heating.
Chlorinated caustic soda is used by heating it to a temperature of 30 ° C. or higher, preferably 50 ° C. to 70 ° C. The effect of the present invention can be obtained equally at a temperature of 70 ° C. or higher, but it may exceed the heat resistance range depending on the material of the bottle. In the method of the present invention, chlorinated caustic soda at a temperature of 30 ° C. or higher is used. It suffices if it is sufficient, it is economical, and it can be used without considering the heat resistance depending on the type of plastic material of the container.

In the present invention, the contact of the chlorinated caustic soda with the inner wall and the outer wall of the container can be performed by spraying, spraying, showering or the like using a nozzle or the like. A method of injecting chlorinated caustic soda in a state where the container is inverted is preferably used because the chlorinated caustic soda is easily discharged from the container. For example, with the container upside down,
In the case of injection to the inner wall of the container, the injection is performed from the opening of the container into the interior of the container using a nozzle or the like. In the case of the outer wall, the injection is performed from a plurality of nozzles or by moving the nozzles. The flow rate of the injection of the chlorinated caustic soda is not particularly limited, but is preferably 50 ml / sec or more, more preferably 150 ml / sec or more, and 2 seconds or more with respect to the inner or outer wall of the container. Preferably, the injection is performed for 5 seconds or more.
The amount of chlorinated caustic soda used when spraying on the inner or outer wall of the container should be at least 0.2 times the internal volume of the container to be sterilized,
Preferably, an amount of 0.5 times or more is used. When such an amount of chlorinated caustic soda is used, the inner wall or the outer wall of the container to be sterilized can be uniformly contacted, and the sterilization can be performed efficiently and completely.

When the chlorinated caustic soda is fully injected into the container for contact with the inner wall, chlorinated caustic soda may be injected with a nozzle or the like, or the container may be filled into a tank filled with chlorinated caustic soda. This can be achieved by immersing the chlorinated caustic soda into the entire interior. Similarly, when the container is completely immersed and held in chlorinated caustic soda for contact with the outer wall, the entire container may be immersed in a tank filled with chlorinated caustic soda or the outer wall of the container may be used. When maintaining the state in which chlorinated caustic soda has flowed down, the chlorinated caustic soda continues to be injected into the container even when the amount is full or more to overflow the chlorinated caustic soda, and the state in which the chlorinated caustic soda flows down the outer wall of the container is maintained. That can be done. In the case where chlorinated caustic soda is fully charged into the container and drained after holding, the liquid is drained after holding for 10 seconds or more, preferably 30 seconds or more from the time when the container becomes full. When the container is immersed in chlorinated caustic soda, the container is kept for 10 seconds or more, preferably 30 seconds or more, from the time when the entire container is completely immersed in chlorinated caustic soda. Similarly, when maintaining the state in which chlorinated caustic soda has flowed down to the outer wall of the container, hold for 10 seconds or more, preferably 30 seconds or more after the chlorinated caustic soda flows down in the entire container. Do.

[0012] The container is immersed in a tank filled with chlorinated caustic soda, and the chlorinated caustic soda is allowed to penetrate into the container, or the chlorinated caustic soda overflows by continuously injecting the chlorinated caustic soda into the inside of the container even if it is full. When the chlorinated caustic soda flows down the outer wall of the container, the contact of the inner and outer walls with the chlorinated caustic soda is
You can do it all at once.

As the water, any water can be used as long as it has no unpleasant odor and sterile water suitable for drinking. The temperature is not particularly limited, but may be any temperature at which fluidity can be sufficiently maintained. Washing of the inner and outer walls of the container with water can be performed by spraying, spraying, showering, or the like using a nozzle or the like. A method of injecting water in a state where the container is inverted is preferably used because water is easily discharged from the container. For example, in the case of spraying on the inner wall of the container with the container inverted, from the container mouth,
Injection is performed by a nozzle or the like into the inside of the container, and in the case of an outer wall, injection is performed from a plurality of nozzles or by moving nozzles. The amount of water used is at least 0.1 times the inner volume of the container to be sterilized, preferably by spraying an amount of at least 0.2 times the inner or outer wall, so that the inner or outer wall of the container can be sufficiently contacted, Residual chlorinated caustic soda can be completely removed. The flow rate of water jet is not particularly limited, but is preferably 50 ml / sec or more, more preferably 150 ml / sec or more, and more than 1 second, preferably 2 ml / sec or more, with respect to the inner or outer wall of the container. Inject for at least 2 seconds.

[0014] Alternatively, in the case of cleaning the inner wall of the container, it is sufficient to inject a full amount of water with a nozzle or the like, or by immersing the container in a tank filled with water and allowing the water to penetrate the entire interior. be able to. Similarly, for cleaning the outer wall of the container,
When the container is immersed in water, the entire container may be immersed in a tank filled with water, or when the water is allowed to flow down on the outer wall of the container, the container is filled with water. The above can also be performed by continuing the pouring, causing the water to overflow, and maintaining the state in which the water flows down the outer wall of the container. The container is immersed in a tank filled with water to allow water to enter the inside of the container, or the water is allowed to overflow into the container by injecting more than the full amount of water into the container and the water flows down the outer wall of the container. When maintaining the condition, the inner wall and the outer wall can be washed with water at the same time.

In the present invention, it is efficient and preferable that the contact of the container with the heated chlorinated caustic soda and the washing with water are carried out successively. The contact with the inner or outer wall of the container may be performed simultaneously or sequentially. After contact with the heated chlorinated caustic soda and washing with water, the beverage can be filled into the container as it is.

Example 1 As a plastic container, a PET container having an inner diameter of a mouth of 28 mm and an internal capacity of 2000 ml was used. The inner wall and the outer wall of the container were sterilized under the following conditions.

(Injection method) A PET container is inverted on a bottle conveying device, and the PET container is fed from upper and side shower nozzles.
° C, sodium hydroxide 2W / V% and hypochlorous acid 0.2
A heated chlorinated caustic soda aqueous solution of W / V% is sprayed on the outer wall of the container for 10 seconds (flow rate 150 ml / second), and simultaneously, PE
A heated chlorinated sodium hydroxide aqueous solution of 50 ° C., 2 W / V% of sodium hydroxide and 0.2 W / V% of hypochlorous acid was passed through a nozzle from the mouth of the T container through a nozzle for 10 seconds (flow rate 150 ml).
/ Sec), and water at 15 ° C. was sprayed onto the outer and inner walls of the container for 3 seconds (flow rate: 150 ml / sec).
This sample was designated as A.

Example 2 (Immersion method 1) A PET container having the same size as the PET container used in Example 1 was placed at 30 ° C. and 2 W / V sodium hydroxide.
% And 0.2 W / V% of hypochlorous acid are completely immersed in a tank filled with an aqueous solution of chlorinated caustic soda, and kept for 3 minutes after the air inside the container is completely removed. After the chlorinated caustic soda aqueous solution inside the container is drained, water at 15 ° C. is drained for 3 seconds (at a flow rate of 150 ml).
/ Sec) Sample B was sprayed on the inner and outer walls of the container.
And

Example 3 (Immersion method 2) A PET container having the same size as the PET container used in Example 1 was placed at 30 ° C. and sodium hydroxide 2 W / V.
% And 0.2 W / V% of hypochlorous acid are injected into the inside of the container with a nozzle, and the injection is continued even after the container is full to overflow the chlorinated caustic soda aqueous solution. After keeping the outer wall in a state where the aqueous chlorinated caustic soda solution flows down for 3 minutes and then draining the aqueous chlorinated caustic soda solution inside the container, 1
Sample C was obtained by spraying water at 5 ° C. onto the inner and outer walls of the container for 3 seconds (flow rate: 150 ml / sec).

Example 4 As a plastic container, a PET container having an inner diameter of a mouth of 28 mm and an internal capacity of 2000 ml was used. The inner wall and the outer wall of the container were sterilized under the following conditions.

(Injection method) The PET container is inverted on the bottle transporting device, and 65 mm from the upper and side shower nozzles.
° C, sodium hydroxide 1W / V% and hypochlorous acid 0.1
A heated W / V% chlorinated caustic soda aqueous solution is sprayed onto the outer wall of the vessel for 5 seconds (flow rate 150 ml / sec), and simultaneously PE
A heated chlorinated sodium hydroxide aqueous solution of 65 ° C., sodium hydroxide 1 W / V% and hypochlorous acid 0.1 W / V% was passed through a nozzle from the mouth of the T container through a nozzle for 5 seconds (flow rate 150 ml /
Second) water was sprayed on the inner wall of the container, and then water at 15 ° C. was sprayed on the outer wall and inner wall of the container for 3 seconds (flow rate 150 ml / second). This sample was designated as D.

Example 5 (Immersion method 1) A PET container having the same size as the PET container used in Example 4 was placed at 50 ° C. and 1 W / V sodium hydroxide.
% And 0.1 W / V% of hypochlorous acid are completely immersed in a tank filled with an aqueous solution of chlorinated caustic soda, and kept for 1 minute after the air inside the container is completely removed. After the chlorinated caustic soda aqueous solution inside the container is drained, water at 15 ° C. is drained for 3 seconds (at a flow rate of 150 ml).
/ Sec) Sample E was sprayed on the inner and outer walls of the container.
And

Example 6 (Immersion method 2) A PET container having the same size as the PET container used in Example 4 was placed at 50 ° C. and 1 W / V sodium hydroxide.
% And 0.1 W / V% of hypochlorous acid are injected into the inside of the container by using a nozzle, and the injection is continued even after the container is full to overflow the chlorinated caustic soda aqueous solution. After the outer wall was kept for 1 minute while keeping the chlorinated caustic soda aqueous solution flowing down, after the chlorinated caustic soda aqueous solution inside the container was drained, 1
Sample F was obtained by spraying 5 ° C. water on the inner and outer walls of the container for 3 seconds (flow rate: 150 ml / sec).

Example 7 As a plastic container, a PET container having an inner diameter of a mouth of 28 mm and an internal capacity of 2000 ml was used. The inner wall and the outer wall of the container were sterilized under the following conditions.

(Injection method) The PET container is inverted on the bottle conveying device, and 65 mm from the upper and side shower nozzles.
° C, sodium hydroxide 2W / V% and hypochlorous acid 0.2
A heated W / V% chlorinated caustic soda aqueous solution is sprayed onto the outer wall of the vessel for 5 seconds (flow rate 150 ml / sec), and simultaneously PE
A heated chlorinated sodium hydroxide aqueous solution of 65 ° C., 2 W / V% of sodium hydroxide and 0.2 W / V% of hypochlorous acid was passed through a nozzle from the mouth of the T container through a nozzle for 5 seconds (flow rate 150 ml /
Second) water was sprayed on the inner wall of the container, and then water at 15 ° C. was sprayed on the outer wall and inner wall of the container for 3 seconds (flow rate 150 ml / second). This sample was designated G.

Example 8 As a plastic container, a PET container having an inner diameter of a mouth of 28 mm and a capacity of 2000 ml was used. The inner wall and the outer wall of the container were sterilized under the following conditions.

(Injection method) The PET container is inverted on the bottle conveying device, and 65 mm from the upper and side shower nozzles.
Chlorinated caustic soda aqueous solution containing 0.5 W / V% of sodium hydroxide and 0.1 W / V% of hypochlorous acid at room temperature.
For 0 second (flow rate 150 ml / sec), it is sprayed on the outer wall of the container, and at the same time, from the mouth of the PET container through a nozzle at 65 ° C, sodium hydroxide 0.5 W / V% and hypochlorous acid 0.05 W /
A heated V% chlorinated caustic soda aqueous solution was sprayed on the inner wall of the vessel for 10 seconds (flow rate 150 ml / sec), and then water at 15 ° C. was sprayed on the outer and inner walls of the vessel for 3 seconds (flow rate 150 ml / sec). This sample was designated as H.

Into a PET container sample A, B, C, D, E, F, G and H having been subjected to the outer wall treatment and the inner wall treatment described above, a sterile liquid medium is filled at room temperature in a clean room, and the container opening is filled with a sterile cap. Part was wound up. As the liquid medium, trypticase soy broth (manufactured by BECTON DICKSON & CO) was prepared at a concentration of 1/10 and sterilized. The composition of the medium used was 1.7 parts of casein hydrolyzate.
g / l, soy hydrolyzate 0.3 g / l, sodium chloride 0.
It was 5 g / l, dipotassium phosphate 0.25 g / l, and dextrose 0.25 g / l. P filled with liquid medium
ET container samples A, B, C, D, E, F, G and H
Were prepared and stored at room temperature. After 1 month and 12 months, the opened and filled liquid medium was observed, but none of them was deteriorated.

Further, the P on which the above-mentioned outer wall treatment and inner wall treatment have been carried out.
ET container samples A, B, C, D, E, F, G and H
Then, a sterile mineral water was filled at room temperature in a clean room, and the container opening was closed with a sterile cap.
A plurality of PET container samples A, B, C, D, E, F, G and H filled with the mineral water were prepared, stored at room temperature, opened and filled after 1 month and 12 months, respectively. Observed mineral water showed no deterioration and had no problem in storage stability, the flavor of the mineral water was not impaired, there was no off-flavor, and no functional change was recognized.

[0030]

According to the method of the present invention, it is possible to sterilize the inner and outer walls of a plastic container by contacting the inner and outer walls of the chlorinated caustic soda and washing with water. .

By the washing with water, the bactericide is effectively washed away, so that the bactericide does not remain on the inner and outer walls of the container, has no effect on the beverage packed in the container, and is easily and efficiently used. It is possible to completely and completely sterilize the inner and outer walls of the plastic container.
Therefore, the flavor of the beverage filled in the container after sterilization is not impaired, and the safety of the beverage is not impaired. In addition, since the chlorinated caustic soda and water can completely sterilize the beverage, the shelf life of the beverage is good. Further, since the present invention can be applied without considering the heat resistance of the material of the plastic container, a material suitable for a beverage packed in the container can be freely selected, and the sterilization method of the present invention can be applied.

Claims (5)

[Claims] 1. A beverage plastic container characterized in that a heated chlorinated caustic soda is brought into contact with an inner wall and an outer wall of a beverage plastic container and further washed with water to sterilize the beverage plastic container. Container sterilization method. 2. The contact of the heated chlorinated caustic soda according to claim 1 with the inner wall of the container is performed by spraying the heated chlorinated caustic soda or filling the inside of the container with the heated chlorinated caustic soda. A method of sterilizing a plastic container for beverages, comprising draining after holding. 3. The contact of the heated chlorinated caustic soda according to claim 1 with the outer wall of the container is performed by spraying the heated chlorinated caustic soda, and completely immersing and holding the container in the heated chlorinated caustic soda. Or a method of sterilizing a plastic container for beverages, which comprises holding heated chlorinated caustic soda on the outer wall of the container. 4. The heated chlorinated caustic soda according to claim 1, which is a mixture of caustic soda and hypochlorous acid, wherein the concentration of caustic soda is 0.5 W / V% or more and the concentration of hypochlorous acid is 0.1 W / V% or more aqueous solution and the mixed solution is 3
A method for sterilizing a plastic container for beverages, which is heated to a temperature of 0 ° C. or higher. 5. A method for sterilizing a plastic container for beverages, wherein the washing with water according to claim 1 comprises spraying water on an inner wall and an outer wall of the container.