Effects of Nitrite and Sorbate on Bacterial Populations in Frankfurters and Thuringer Cervelat

Four batches of frankfurter emulsion were prepared with no additives, 0.26% potassium sorbate, 140 ppm of sodium nitrite plus 550 ppm of sodium isoascorbate, and 40 ppm sodium nitrite plus 0.26% potassium sorbate plus 550 ppm sodium isoascorbate, and processed. Five batches of thuringer cervelat emulsion were prepared with no additives, 0.26% potassium sorbate, 156 ppm of sodium nitrite, 78 ppm of sodium nitrite plus 0.26% potassium sorbate, and 78 ppm of sodium nitrite plus 156 ppm of sodium nitrate, and processed. The finished products were stored aerobically and bacterial growth patterns were monitored. At 20 C, presence of sodium nitrite and potassium sorbate, separately or together, in the frankfurters were without appreciable effect on total aerobic, total anaerobic, gram-positive, and lactobacillus-pediococcus counts, although at 7 to 9 C these additives moderately lowered bacterial counts. Bacterial counts of the thuringer cervelat were not affected by sodium nitrite, potassium sorbate or sodium nitrate at either temperature. Staphylococcus aureus and Clostridium perfringens were inoculated into all emulsions before further processing to determine if the modified cures, or possible changes in normal microflora, influenced these pathogens. S. aureus was reduced to below detectable levels after heat-processing in all systems. C. perfringens survived processing and then underwent equally slow death in all stored frankfurter emulsions, and stabilization of counts in thuringer cervelat emulsions. Results indicate that the modified cures did not appreciably alter the natural microflora of these products, nor survival of added pathogens.