Behavior of Staphylococcus aureus in refrigerated and frozen ground beef and in Turkish style sausage and broth with and without additives

Staphylococcus aureus 42E was inoculated into raw ground beef which was stored at 4C and -27C. Turkish style sausage and Brain Heart Infusion broth (BHIB), with and without additives were also inoculated with S. aureus and held at 4C. Samples of ground beef and sausage were examined for S. aureus, aerobic plate count and pH values. The numbers of S. aureus cells were decreased by 1.64 and 2.02 log units in ground beef held at 4C after 7 days and -27C after 7 weeks, respectively. A decrease in the number of S. aureus cells was observed in sausage and BHIB with addition of 0.5% trisodium phosphate (TSP), 78 mg/kg sodium nitrate, 78 mg/kg sodium nitrate plus 156 mg/kg sodium nitrate and 78 mg/kg sodium nitrite plus 0.5% TSP. Overall, sodium nitrite either alone or in combination with sodium nitrate was more effective on S. aureus and aerobic bacteria than TSP either alone or in combination with sodium nitrate.