Mechanically deboned poultry meat (MDPM) was used to formulate a fermented sausage product prepared by a natural lactic acid fermentation (fermentation by indigenous lactic acid bacteria). Salted MDPM (3% NaCl) stored at 5 C promoted growth of lactobacilli to a level of 106 cells/g after 12 days. During the same period the population of indigenous Staphylococcus aureus decreased to below a detectable level but no change was observed in the population of added S. aureus (107 cells/g). The MDPM attained a pH of 4.7 after 60 h of fermentation with a corresponding developed acidity of 1.6% expressed as lactic acid. The heat treatment given to the sausage (to attain an internal temperature of 60 C) brought about a reduction in the population of both the lactobacilli and S. aureus (4.1 and 5.6 log cycles, respectively); the latter was decreased to an undetectable level. Acid, sodium chloride and sodium nitrite in combination with a heat treatment (60 C, 60 min) gave the largest reduction of the population of S. aureus resulting with a D-value of 23.6 min. Succinic acid in combination with either a heat treatment (60 C, 60 min) or low temperature storage (7 C, 7 days) was the most effective treatment against S. aureus. Other acids active against S. aureus arranged in decreasing order of effectiveness were lactic, acetic and citric.
1Present address: Microlife Technics, Box 3917, Sarasota, FL 33578.