Post-Lethality Environment of Very Small Processing Plants for Listeria Species
University of Wisconsin-Madison, WI
Drs. Dennis R. Buege and Steven C. Ingham
The purpose of this audit was to sample food contact and non-food contact surfaces in the post-lethality environment to determine if and where Listeria contamination is a problem in small and very small plants.
Because Listeria is so widely distributed in the environment, it is very likely that it would be found on both food and non-food surfaces in food establishments. It is recommended that post-lethality contact surfaces be re-sanitized directly before use when such equipment/surfaces are not used every day. Food contact surfaces that were positive for Listeria were found on slicers, surfaces of packaging tables/carts, internal cavity of chamber vacuum packaging equipment, and tubs/lugs that hold RTE product.
Non-food contact surfaces that reveal a particularly high rate of incidence for Listeria were floors and drains. It is recommended that processors work with sanitation suppliers to develop a sound floor and drain sanitation program. Such a program may include routine scrubbing of floors and drains, application of high levels of quat sanitizers (800+ ppm), limiting use of high pressure hoses and altering/limiting employee foot traffic where possible.
The result of this audit of smaller-scale plants provides operators with a snapshot of the Listeria status of the post-lethality environment over a wide range of plants. Knowing where this pathogen is likely to be found in operations similar to their own will aid processors in addressing the challenge of controlling Listeria in the post-lethality environment. As this information was being collected it was shared with the participating plants and the state extension service so they could provide general assistance to the industry for identifying Listeria contaminated surfaces.
The full report on this research can be found on the Fiscal Year 2003 table under the column Food Safety Technologies - Additional Information.