The science and statistics underlying sound microbiological sampling and testing approaches

The importance of food safety is at an all-time high and it remains an important priority for many stakeholders around the world, including food enterprises, regulatory agencies and consumers. To manage and assess food safety risks, a variety of methods and tools are available, including microbiological testing of foods. Microbiological testing can be applied at all stages of food production from the farm to manufacturing facilities to the retail level. When using microbiological testing to assess the safety of a food, it is important to select the appropriate test method and sampling plan, based on good understanding of the underlying statistics as well as knowledge of the limitations of such testing. In the session, the statistics underlying useful testing will be elaborated on, providing examples of how microbiological criteria are developed and sampling plan performance is assessed. Sampling by nature is a stochastic process. However, uncertainty regarding results is made even greater by the uneven distribution of microorganisms in a batch of food. Different batch contamination scenarios are illustrated: a homogeneous batch and a heterogeneous batch with high- or low-level contamination.