The prevalence of
E. coli on the surfaces of zone 1 was 0.5% when production began,
increasing throughout the production run to 1.9% at the end. The
main cleaning at the end of production each day reduced the
E. coli prevalence at the start of the next day’s production, and
although it did not negate it the prevalence of E. coli was so low
and patchily distributed in zone 1 that perhaps this is why no
E. coli contamination was detected in the finished product at any
time. Regardless, it is consistent with the fact that good controlling
of the processing environment, and particularly the direct food
contact areas (zone 1), affects the product contamination level