JPS629826Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a heat sterilization indicator used to determine the state of extermination of microorganisms attached to a hermetically packaged food or the like when the food is heat sterilized. More specifically, it relates to a microbial indicator for heat sterilization that utilizes microbial spores and the like and a culture medium necessary for the growth of the microorganisms.

Conventionally, methods for determining the state of death of microorganisms due to heat sterilization include methods in which a thermocouple temperature sensor is used to measure the temperature at the center of the food during heat sterilization and the state of death of microorganisms is determined by calculation from this, and a method for determining the state of death of microorganisms by calculation. There is a method of embedding an indicator consisting of food, etc. in food, removing the indicator after heat sterilization, and culturing it in a culture medium to determine the dead state. The former method requires an expensive temperature sensor and temperature measuring device, has the disadvantage that the number of samples to be measured is limited, and cannot be used when a continuous heat sterilizer is used. On the other hand, the latter method using a microbial indicator does not have the above-mentioned drawbacks and is a practical method, but there is a desire for the development of a simpler microbial indicator.

Currently, there are microbial indicators on the market that have microbial spores coated on paper.
The drawback is that microbial spores are dispersed from the paper when removed from the food, making it impossible to determine whether they were killed by heating or dispersed in the food. Furthermore, it requires equipment and time to aseptically remove the food from the food after heat sterilization and transfer it into the culture medium. In order to improve this drawback, we have developed a microbial indicator in which paper coated with microbial spores and culture medium are separately filled and sealed in the same container, and after heat sterilization, the partition between the two is destroyed from the outside of the container to mix the two. has been done. However, in this case, during heat sterilization, the microbial spores in the indicator are isolated from the culture medium, so they are sterilized in a dry heat state where they cannot absorb moisture from anywhere.
It is unsuitable as a microbial indicator because its true bactericidal effect is unknown. This is because food sterilization usually involves discussion of killing food under moist heat conditions.

The present invention improves the drawbacks of the conventional indicators described above, and provides a microbial indicator for heat sterilization that allows more appropriate testing and is easier to handle.

Hereinafter, the present invention will be explained in detail with reference to the drawings. In the figure, 1 is an ampoule-shaped sealed container body made of heat-resistant thermoplastic resin (for example, polypropylene) or heat-resistant glass. A partition 2 made of thermoplastic resin (e.g., hot melt adhesive) having a melting point of, for example, 60°C to 100°C is provided in the center of the main body 1, and the interior of the main body 1 is completely divided into two chambers. Ru. One chamber 3 is filled with microbial spores or vegetative cells 4 coated on paper 5 or dispersed in a buffer solution, and the other chamber 6 is filled with microbial spores or vegetative cells 4 for the growth of microorganisms 4. A suitable culture medium, such as a natural culture medium, a synthetic culture medium, a liquid culture medium, or a solid culture medium 7 obtained by adding agar or gelatin to the solid culture medium, is filled and sealed.

Next, a method of using the microbial indicator for heat sterilization of the present invention will be explained.

First, the indicator of the present invention is embedded in the center of an object to be heated (not shown) such as a packaged food, and conventional heat sterilization such as boil sterilization or pressure heat sterilization is performed. Only the desired package is embedded with an indicator. In some cases, it is simply inserted between packaged products. As the food is heated, the indicator is also heated by heat transfer, and when heated to 60°C to 100°C, the partition 2 melts and the microorganisms 4 and culture medium 7 are mixed, and heat sterilization continues in this state. It will be done. Even when a solid culture medium is used, the agar and gelatin in the solid culture medium liquefy due to heating, so the microorganisms and culture medium are mixed.
Microorganisms are sterilized with moist heat. After heat sterilization is completed and the food is cooled, the indicator is removed from the food and cultured at the temperature at which microorganisms grow. After culturing,
If the culture medium 7 becomes cloudy or discolored, this indicates that the microorganisms 4 have grown, and indicates that the microorganisms were not killed by heat sterilization. Conversely, if there is no change in the culture medium, this indicates that the microorganisms were killed by heat sterilization. In other words, if there is a change in the culture medium in the indicator, the sterilization of the food, etc. is insufficient, but if there is no change, the sterilization of the food, etc. has been sufficient. Even if it is sealed inside, it is possible to indirectly know whether the sterilization inside is appropriate or not.

As mentioned above, the feature of the indicator of the present invention is that the inside of the heat-resistant container body is divided into two parts by a partition made of thermoplastic resin with a melting point lower than the predetermined sterilization temperature, and microorganisms etc. The culture medium is filled and encapsulated in each container. Therefore, according to the present invention, the partition can be removed during sterilization, the microorganisms and the culture medium can be mixed, and the microorganisms can be placed in a moist heat state, so that the sterilization effect can be appropriately evaluated.

Furthermore, compared to conventional indicators, it is easier to handle because it does not require any operation to destroy the partition from the outside of the container. In addition, by changing the type and number of microorganisms in the indicator,
The sterilization effect of heat sterilization can also be evaluated step by step.

[Brief explanation of drawings]

The figure is a vertical sectional view of an example of an indicator according to the present invention. 1... Sealed container body, 2... Partition, 4... Microorganism, 7... Culture medium.

Claims (1)

[Scope of utility model registration request] It comprises a container body made of heat-resistant resin or heat-resistant glass, and a partition made of thermoplastic resin having a melting point lower than the predetermined sterilization temperature of the food to be sterilized, provided in the center of the body, A microorganism indicator for heat sterilization, characterized in that one chamber of the container body separated by the partition is filled with microorganisms or their spores, and the other is filled with a culture medium for the microorganisms.