Inhibitory effects of organic acid salts for control of Listeria monocytogenes on frankfurters.

Sodium diacetate (SD), sodium diacetate plus potassium benzoate (SD-PB), and sodium lactate plus sodium diacetate plus potassium benzoate (SL-SD-PB) were selected for initial effectiveness against Listeria monocytogenes on frankfurters. Treatments were evaluated at -2.2, 1.1, 4.4, 10.0, and 12.8 degrees C for up to 90 days. The compounds were applied as 3 or 6% (total concentration) dipping solutions for surface treatment of the frankfurters. The treated frankfurters were inoculated with a five-strain cocktail of L. monocytogenes (Scott A 4b, H7764 1/2a, H7962 4b, H7762 4b, and H7969 4b) using 1 ml of 10(4) cells for each 90.8-g package of two frankfurters. The maximum population of L. monocytogenes was decreased and generation time and lag phase were increased after surface treatments with 6% SD, 6% SL-SD-PB, 3% SD-PB, and 6% SD-PB solutions at 1.1 degrees C. Surface treatment of frankfurters with SD at 6% was more effective for inhibiting L. monocytogenes growth than were the other treatments. Under the conditions of this study, L. monocytogenes survived in refrigerated storage even in the presence of the additives tested.