Listeria monocytogenes is a psychrotrophic foodborne pathogen that has been isolated from ready-to-eat
meat and poultry products (RTE meats). The purpose of this study was to quantify lactate and acetate
levels in retail RTE meats that had been tested in a previous study for the presence of L. monocytogenes to
correlate the occurrence of L. monocytogenes to the acid levels. Products were extracted after blending
50 g of each sample with de-ionized water, and the extracts were quantified for lactate and acetate using
HPLC. In general, the concentrations of both acids in samples varied with product types and manufac-
turers (p < 0.05). The mean concentrations of lactate and acetate ranged from 10.71 to 23.03 mg/g (1.07
e2.30%) and 0.66e1.56 mg/g (0.066e0.156%), respectively. The mean concentrations of lactate and ac-
etate in L. monocytogenes-positive samples were 1.13e24.05 mg/g (0.11e2.4%) and 0e5.74 mg/g (0
e0.574%), respectively. Results of this study indicate that RTE meats containing low levels of lactate were
more likely to be positive for L. monocytogenes while samples with higher concentrations of lactate and
acetate were less likely to be positive for the pathogen. Therefore, the addition of lactate and acetate as
antimicrobials is helpful as part of an overall Listeria control program. However, a rigorous sanitation and
an effective HACCP program are also essential for control of Listeria.