Virginia Tech
Survival of Listeria monocytogenes, Listeria innocua, and Lactic acid bacteria species in chill brine
Abstract
dc:description.abstractListeria monocytogenes is the major pathogen in ready-to-eat meat products such as deli meats and frankfurters. Contamination can occur via the salt brines that are used to cool thermally processed meats. Both L. monocytogenes and lactic acid bacteria can grow and thrive under these brine conditions, and may become competitive with each other for available nutrients. The objective of this study was to determine the effect of a three strain cocktail of lactic acid bacteria Enterococcus faecalis, Carnobacterium gallinarum, and Lactobacillus plantarum on the survival of Listeria monocytogenes and Listeria innocua in brines stored under low temperatures up to 10 days. Three brine concentrations (0%, 7.9%, and 13.2% NaCl) were inoculated with ~7.0 log₁₀ cfu/ml of one of five cocktails (L. monocytogenes, L. innocua, lactic acid bacteria (LAB), L. monocytogenes + LAB, or L. innocua + LAB) and stored for 10 days at either 4°C or 12°C. Three replications of each brine/cocktail/temperature combination were performed. No reductions of L. monocytogenes were seen in 7.9 or 13.2% NaCl with LAB; however, reductions of L. monocytogenes were seen in the 0% NaCl with LAB (1.43 log at 4°C and 3.02 log at 12°C). Listeria innocua was significantly less resilient to environmental stresses than L. monocytogenes, both with and without LAB present (p<0.05). This research indicates these strains of lactic acid bacteria are not effective at reducing L. monocytogenes in brines at low temperatures. Furthermore, the use of L. innocua as a model for L. monocytogenes is not appropriate under these environmental conditions.
Degree
thesis:*- Name thesis:degree_name
- Master of Science
- Level thesis:degree_level
- masters
- Discipline thesis:degree_discipline
- Food Science and Technology
- Department dc:contributor.department
- Food Science and Technology
- Grantor dc:publisher
- Virginia Tech
- Year dc:date.issued
- 2004
Author and committee
dc:creator, dc:contributor.*- Author dc:creator
-
- Meadows, Bridget Archibald
- Chair dc:contributor.committeechair
-
- Sumner, Susan S.
- Committee members dc:contributor.committeemember
-
- Williams, Robert C.
- Eifert, Joseph D.
Subjects
dc:subject × 4Rights
dc:rights- Statement dc:rights
-
- In Copyright
- Licence dc:rights.uri
Identifiers
dc:identifier.*- Dc Identifier Other
- etd-05272004-181730
- OAI identifier oai:identifier
- oai:vtechworks.lib.vt.edu:10919/9970