Pasteurization of vacuum-sealed packages of summer sausage inoculated with Listeria monocytogenes

Packages containing chubs of summer sausage were inoculated with about 10(8) cfu/mL of a three-strain mixture of Listeria monocytogenes and vacuum sealed. The fate of the pathogen was then monitored after pasteurization at 150F (66C), 170F (77C), 190F (88C) and 210F (99C) for 0 to 240 s. Pathogen numbers were reduced by about 3 log(10) cfu per grant within 30, 60, or 90 s at 210F (99C), 190F (88C), or 170F (77C), respectively, whereas numbers were reduced by <2.0 log(10) cfu per gram after 240 s of heating at 150F (66C). The calculated D values were 2.08 min at 150F (66C), 0.84 min at 170F (77C), 0.37 min at 190F (88C), and 0.28 min at 210F (99C). These results establish the feasibility of using pasteurization to control L. monocytogenes in packaged summer sausage.