Surrogates From January 2015 newsletter

Heat process validation: using surrogates

When developing, optimizing and validating a process aimed at eliminating microbial contamination of a food product, there comes a point at which the actual factory process must be evaluated, to provide verification that the microorganism of concern is sufficiently reduced in the product. Introduction of pathogens or spoilage organisms into a commercial processing environment would pose an unacceptable risk to food safety/spoilage. Timetemperature integrators can be used instead, as can surrogate organisms. These are harmless organisms with similar resistance properties to the microorganism of concern. This project is generating data to support the use of definitive surrogate organisms, investigating their suitability across different food groups and process types.

A range of surrogates are being evaluated for their suitability to mimic Salmonella, Listeria monocytogenes, Bacillus cereus and Byssochlamys in a range of products. These all have different growth and heat resistance properties, and are a potential problem with different food types. Initial studies have demonstrated that the surrogate must be matched not only with the pathogen, but also with the food matrix - for example, a surrogate for Salmonella in a chilled, short shelf-life food that is preserved with wet heat may not be suitable for seeds treated by roasting.

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Contact: Rob Limburn
+44(0)1386 842493

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