Efficacia della depurazione sulla sicurezza di mitili (Mytilus galloprovincialis) allevati nel golfo di Olbia

The aim of the present study was to investigate the effect of depuration on the safety of
Mediterranean mussels harvested in the Olbia gulf and to evaluate the efficacy of E.coli
and Salmonella spp. as indicators of the presence of naturally occurring Vibrios and
other pathogens (viruses causing hepatitis, L.monocytogenes and S.aureus). Samples of
mussels belonging to 5 batches of products, from 2 Depuration Centers, were collected
before depuration (T0), after 4h (T4) and at the end of depuration (T8). Results showed
an overall efficacy of the depuration in respect to E.coli moderate counts. A depuration
for ~8 hours led to a rapid decline in the concentration, complying to the Food Safety Criteria
of the Reg. (EC) 2073/2005. The decline in numbers of E.coli, does not correlate
with the presence of naturally occurring Vibrios, which decline at an even slower rate.
The adoption of shorter treatments times for mussels with high initial counts of Vibrios
could lead to a reduction unfitted to guarantee the safety of consumers.