Resistance of Test Germs 2

A main task of hygienically working packaging machines and especially of packaging machines for low acid products (aseptical) is the partial decontamination or the sterilization of the packaging material just before its filling. In case of low acid products mostly hydrogen peroxide as decontaminating agent is used.

For quantifying the efficiency of a device concerning the decontamination (packaging material and the device itself) challenge tests using Bacillus subtilis – spores are carried out. The test microorganisms act as a sensor in form of a bio-indicator. The resistance of the bio-indicator plays an decisive role.

The Fraunhofer IVV developed a reliable, reproducible method for testing the resistance of dried test germs to fluid H2O2.The project was financed by IVLV/FoGe. Now it is possible to measure the resistance of dried test microorganisms to fluid H2O2 exactly. Thus a method is available to compare results from filling machine validations directly (i.e. absolutely not only relatively to each other) by using the D-values of the test organisms.

Aims of the described follow-up project are:

• to match the method found in the forerun project with the demands of FDA (U. S. Food and Drug Administration
• to clarify if a fixed correlation of differently resistant germ suspensions, compiled with fluid H2O2 are valid if the H2O2 is applied in an other way. It should be verified if differences of D-values of different germ suspensions appear in the same manner if the application of the H2O2 varies (aerosol, condensate). If there were differences the measurement of the resistance had to be done depending on the application method. This means that for every single application method another method of measuring the resistance would be necessary.