Inhibition of Listeria monocytogenes by sodium diacetate and sodium lactate on wieners and cooked bratwurst

The inhibition of Listeria monocytogenes by sodium lactate and sodium diacetate was evaluated for wieners containing pork, turkey, and beef and for cooked bratwurst containing beef and pork, Both products were supplied by commercial manufacturers. Treated products were surface-inoculated with 10(5) CFU of L. monocytogenes per package and vacuum-packed in gas-impermeable pouches. Wieners were stored for 60 days at 4.5degreesC, and bratwurst ere stored for 84 days at 3 and 7degreesC. A surface treatment that consisted of dipping wieners into solutions containing less than or equal to67% lactate and less than or equal to3% diacetate for 5 s did not delay pathogen growth compared with that for untreated wieners. In additional trials, the antilisterial activity of lactate and diacetate in wiener and bratwurst formulations was evaluated. Lactate levels ranged from 1.32 to 3.4%, and diacetate was evaluated at 0.1 and 0.25%. The growth of L. monocytogenes was delayed for 4 and 12 weeks at 7 and 3degreesC, respectively. on uncured, unsmoked bratwurst formulated with 3.4% lactate/0.1% diacetate, compared with 1 and 2 weeks', respectively, for the formulation containing 2% lactate. L. monocytogenes grew by greater than or equal to1 log unit after 4 weeks' storage at 3 or 7degreesC on cured, smoked bratwurst without lactate or diacetate, but growth was inhibited for 12 weeks on cured, smoked bratwurst formulated with 3.4% lactate and 0.1% diacetate. Sodium lactate levels of greater than or equal to3% and combinations of greater than or equal to1% lactate plus greater than or equal to0.1% diacetate prevented listerial growth on wieners stored for 60 days at 4.5degreesC. These results indicate that dipping wieners in lactate-diacetale solutions is not an efficient way to apply these antimicrobial agents to wieners, However the inclusion of combinations of sodium lactate and sodium diacetate in wiener or bratwurst formulations inhibits the growth of L, monocytogenes at less than or equal to7degreesC, and an additional margin of safety was observed for products that are cured and smoked.