The implementation of a good challenge test for Listeria monocytogenes in accordance with EU regulations requires more than just a knowledge of microbiology. Obviously we use the right strains of Listeria monocytogenes, we carry out the correct counts and measurements, and we draw up our reports in accordance with EU regulations. But before we start a challenge test for Listeria monocytogenes, we first of all want to know what product it is, what the preservation method being used is, what the desired shelf life is, and whether the desired shelf life is realistic. On the basis of this information we are able to provide our clients in advance with practical, useful advice about the recipe, implementation and further substantiation of the shelf life.
For these tests too, first of all we carry out a proper risk assessment, evaluating the product, process and intended use of the product. On the basis of this risk assessment we put together a cocktail of strains that are relevant for the identified risks and set up a test that complies with the identified risks. In our dedicated pathogen lab we carry out challenge tests for salmonella and other pathogens that are tailored to suit our clients.
For on-site validation of heating processes we use harmless substitutes for Salmonella ssp and Listeria monocytogenes. These surrogates have the same properties as the pathogens but are completely harmless.
Take a look at all our news reports linked to challenge testing for practical examples.