For zone 1, E. coli contamination was found before production
started, but only at the bolt heads on the side of the chiller declining
belt. With their small cleft, which makes them difficult to clean
and so often neglected, they became cumulative points of contamination.
During production, E. coli spread, presumably by cross contamination
from these points, to the swings of the chiller and
freezer declining belts. By the time production ended, E. coli had
further spread to the surfaces of the chiller declining belt, chiller
and freezer wire mesh belts and the cutting boards at the dicing
area. For enterococci, some parts of the transfer belt (e.g. the swing
of the freezer declining belt) that were incompletely cleaned and sanitized, were the important reservoir sources of zone 1 contamination.
In the same manner as E. coli discussed above, contamination
of enterococci appeared to distribute throughout the
processing line during the day’s production, but was more marked
having a greater number of initiation focisites and final contamination
levels