E.coli control in fermented sausages

New techniques to minimise the risk of harmful food pathogen E.coli in fermented dry sausages could be on the way as scientists find acidic conditions encountered during the digestive process may not be enough to inactivate some harmful bacteria in fermented dry sausages.

Escherichia coli O157:H7 is one of the leading causes of foodborne diseases and can result in severe compli-cations in humans ranging from haemorrhagic colitis to death.

Previous outbreaks have been primarily associated with ground beef and raw milk, but a recent increase in cases involving highly acidic foods such as fermented dry sausages, mayonnaise, and apple cider have raised new concerns.

For this latest study, fermented dry sausages were inoculated with E.coli O157:H7 and exposed to synthetic saliva for one minute, synthetic gastric juice for 120 minutes, and synthetic pancreatic juice for 250 minutes.

Results showed that not only did existing E.coli O157:H7 cells remain viable after exposure to both synthetic saliva and gastric juice, they began to grow at a significant rate when exposed to the pancreatic juice.

"From a food safety point of view, this implies that the industrial processes used to manufacture sausages must be designed in such a way that no viable E.coli O157:H7 cell can ever be found in an average portion of sausage for human consumption, because no additional protection will be afforded by the subsequent digestive process," say the study researchers from the Agriculture and Agri-Food Canada food research and development centre in Quebec.

"This new information will be very valuable in refining our assessment of the risk associated with the manufacture of fermented dry sausages with regard to E.coli O157:H7," they add.

Full findings of the study are published in the November issue of Applied and Environmental Microbiology 70, 11: 6637-6642.