Fate of Salmonella in dry confectionery raw materials

To study the behaviour of salmonellae inoculated in the dry, raw materials, related to chocolate confectionery manufacture, as affected by the strain, cell preparation method and storage temperature.

Outbreak and non outbreak-associated salmonellae were used for the inoculation of cocoa butter oil, crushed cocoa and hazelnut shells, cocoa beans and almond kernels. Dry matrices were inoculated with lawn-collected and broth-grown cells and were stored at 5 and 21 degrees C for 21 days. Results demonstrated that all strains survived in all dry matrices. Lawn-collected cells survived considerably better than broth-collected cells, at either temperature, and outbreak-associated strains of Salmonella serotype Enteritidis PT30 and Salmonella serotype Oranienburg appeared to be among the best surviving strains.

The work demonstrated that salmonellae can survive storage for 3-4 weeks in dry raw materials and that survival is dependent on the source of strains, cell preparation and inoculation methodology, and storage temperature.

The data contributes to understanding the parameters to consider when assessing the risk of dry raw materials as the most likely source of salmonellae in chocolate processing plants. It also demonstrates the importance of implementing effective lethal processes and segregation procedures to prevent cross-contamination to ensure the safety of confectionery products regarding Salmonella.