A bacteriocin-producing Pediococcus species inhibitory to Listeria monocytogenes was used to manufacture fermented semidry sausage. Separate 13.6 kg batches of a commercial summer sausage formulation were inoculated to contain an initial level of 106 cells/g of Listeria monocytogenes Scott A. In each of two independent studies, an ca. 2 log10 CFU/g reduction of L. monocytogenes occurred over the fermentation period, as compared to a less than 1 log10 CFU/g reduction in sausage fermented with a non-inhibitory Pediococcus strain. Inactivation of L. monocytogenes was also observed in one study where adequate acid production did not occur (pH>5.5), indicating that bacteriocin production occurred independently of carbohydrate fermentation. Following heating to an internal temperature of 64.4°C and storage up to 2 weeks, 9 of 90 sausages sampled were positive for Listeria. Recovery was intermittent and did not indicate that the bacteriocin was effective in eliminating L. monocytogenes that had survived the heating process.
1Published as paper No. 8955, Journal Series Nebraska Agricultural Experiment Station, Lincoln, NE 68583-0919.
2Department of Food Science and Technology.
3General Mills, Inc.
4Department of Animal Science.