Staphylococcus aureus Growth and Toxin Production in Nitrogen-Packed Sandwiches ¹

Plastic-enclosed sausage, hamburger and turkey sandwiches were inoculated with enterotoxigenic Staphylococcus aureus to evaluate the potential hazard of staphylococcal food poisoning in sealed foods maintained in an N₂ environment. The effect of such food storage on staphylococcal growth and enterotoxin production was determined under varying conditions of time (1-31 days) and temperature (8, 12, and 26 C). At 8 and 12 C, none of the sandwiches became toxic after 31 days of storage; however, at 26 C, sausage and hamburger sandwiches became toxic at days 2 and 4, respectively, while remaining organoleptically acceptable. Turkey sandwiches did not support sufficient growth of staphylococci to allow the production of detectable amounts of enterotoxin at any of the temperatures tested.