Photo: National Food Institute, Technical University of Denmark

Better data for risk assessment

Wednesday 22 Jan 14


Ana Sofia Ribeiro Duarte
National Food Institute

It is difficult and expensive to collect the type of data on which food producers and public authorities base their risk assessment of foods. A PhD project at the National Food Institute, Technical University of Denmark, has developed new methods to predict the number of bacteria in foods on the basis of the number of bacteria found in the laboratory.

Foods may contain bacteria such as Salmonella, Listeria or Campylobacter, which may cause disease in humans. It is, thus, important to develop methods which predict the amount of bacteria in foods as precisely as possible to be able to improve food safety.

Food producers and public authorities use QMRA, quantitative microbiological risk assessment, as a tool to estimate the number of disease cases of humans who have eaten food with a specific bacteria, and to assess the effect of control measures in food production. QMRA consists of mathematical models and data for risk assessment.

More precise data for analyses

The QMRA results depend on the amount of data on bacteria in foods. In her PhD project Ana Sofia Ribeiro Duarte investigated whether the way to analyse data could be improved, and whether the data already at hand could be used more effectively.

Data from the laboratory are suitable

The project focused on two specific problems: Is it possible to develop a mathematical model, which uses data from the laboratory, to predict the actual number of bacteria in a particular food product from food production undertakings? Are data from laboratory tests suitable for validating mathematical models which predict the number of bacteria in food?

The tests have contributed to establish the interpretation of laboratory analyses and suggest guidelines for validating the mathematical models. On the basis of laboratory analyses the project has developed new methods to predict the actual number of bacteria in foods.

Read more

See Ana Sofia Ribeiro Duarte’s PhD thesis: The interpretation of quantitative microbiology data: meeting the demands of quantitative microbiological risk assessment (pdf).

Read more about research in risk assessment at the National Food Institute.