The Institute of Food Research (IFR) has teamed up with Italian and Greek scientists to develop a tool for predicting Salmonella levels at different stages of the pork supply chain.
To make predictions, the new software relies on a database of previous research results as well as input from users on actual processing conditions.
Factors affecting Salmonella growth
Temperature, pH and water activity (a measure of food dryness) have to be entered for the tool to give accurate forecasts. This is because these factors all have an impact on the growth and survival of Salmonella and can vary across the supply chain and from one processing environment to another.
The team behind the new tool explained that the way Salmonella levels vary, depending on the production stage and environmental conditions, makes predicting growth of the bacteria difficult.
“Tracing the cause of bacterial contamination to a particular stage of the supply chain can be difficult because of uncertainty surrounding how the bacteria grow at the different stages and under different environmental conditions.”
Tapping into international microbial database
To develop a tool capable of modelling the growth of Salmonella in pork, the researchers turned to Combase – a database on microbial growth in different environments.
Developed by IFA in collaboration with USDA Research Service and Australia’s Food Safety Centre, Combase contains over 700 records describing growth of Salmonella in a wide variety of conditions relevant to the pork supply chain.
Different models were then combined to give predictions on the concentrations of Salmonella at different production stages and under varying temperature, water activity and pH levels. Predictions can be made with inputs ranging from 0-30°C, 2.5 - 7 pH and 0.78-1 for water activity.
The estimates obtained from the software were validated by comparing them against actual Salmonella levels in several pork products.
Funding for the work was provided by the European Union-funded Biotracer programme – which is aiming to improve traceability of microorganisms in food and feed.
Source: International Journal of Food Microbiology
Volume 145, Supplement 1, 1 March 2011, Pages S96-S102
Modelling Salmonella concentration throughout the pork supply chain by considering growth and survival in fluctuating conditions of temperature, pH and aw
Authors: Carmen Pin, Gaspar Avendaño-Perez, Elena Cosciani-Cunico, Natalia Gómez-Tomé, Antonia Gounadakic, George-John Nychas, Panos Skandamis and Gary Barker.