Food washing process may be causing outbreaks of poisoning

Outbreaks of food poisoning could be caused by an industry standard cleaning procedure used for fresh produce like salads, according to scientists in the UK.

The researchers, at the University of Southampton, said the practice of washing fresh produce with chlorinated water is supposed to kill or reduce the number of bacteria on food but it is actually making them undetectable.

β€œIt is good standard practice to chlorinate, disinfect foods to reduce those numbers but our work is showing in fact that this is masking the problem and you may not be killing the pathogens at all.” – Professor Bill Keevil, Head of the Microbiology Group at the University of Southampton

The team have shown that many bacteria survive the stress of coming into contact with chlorine by shutting down or becoming viable but nonculturable, a state that also renders them invisible to standard laboratory safety tests.

Furthermore, they have also shown an alternative, molecular bacterial detection techniques used by some laboratories to test food safety are also unreliable.

Outbreaks of food poisoning are blamed for more than 400,000 deaths, according to the World Health Organisation. In the UK, the government estimated a million people a year suffer a foodborne illness, resulting in 500 deaths.