that has a demonstrated record of success is steaming the entire packaging
line. This technique has proven effective
for a packaging line that had an ongoing
problem with Listeria contamination,
but a niche could not be identified.
Scheduling this equipment cooking
process into the preventative maintenance schedule of the processing facility
can prevent the development of a
Maintenance tools, if not controlled,
can be problematic with regard to contamination and transfer of microorganisms of concern. Maintenance personnel
and tools should be dedicated to raw or
cooked areas within the processing facility. Hand-held tools should be cleaned
and sanitized daily and stored in a sanitary manner. Some processors have reported success with scheduled “cooking”
of maintenance tools, which is built into
the preventative maintenance schedule.
Brine chill systems are used for chill-
ing certain deli meats and link products.
These systems, although high in salt con-
centration, can easily become contami-
nated with Listeria and can serve as po-
tential harborage sources that can affect
multiple lines of packaged product.
Brine chill systems pose a significant risk
as a source of bacterial contamination,
and all products produced with these
systems are vulnerable to cross-contami-
nation. The use of citric acid to lower
the pH of these brines has proven suc-
cessful at inactivating L. monocytogenes
and preventing cross-contamination.
Acidifying brine chill systems with citric
acid is an effective treatment in control-
ling Listeria in these systems, as long as
the pH remains in the 3.0– 3. 5 range (un-
published data). The pH should be mon-
itored throughout the production day to
verify the pH is in the appropriate range.
Robin M. Kalinowski, M.S., is a Research
Project Manager at the Silliker, Inc. Food
Science Center, South Holland, IL. She
possesses over 20 years of food industry
experience and can be reached at
5. Tompkin, R.B. 2002. Control of Listeria monocytogenes in the food-processing environment. J Food