Thermal inactivation and injury of Clostridium sporogenes spores during extrusion of mechanically deboned turkey mixed with white corn flour

An extruded mixture of mechanically deboned turkey and white corn flour was used as a model system to study the thermal inactivation and injury of Clostridium sporogenes spores. Thermal inactivation was observed at 93.3 C (2 log(10) reductions) and 115.6 C (4-5 log(10) reductions). Statistical analyses showed that significant difference in thermal inactivation of spores occurred between the extrusion temperatures (P 0.05). C. sporogenes spore counts of the extruded sample from a rich protein medium (Brewer Anaerobic Agar) were significantly greater than those from a limiting growth medium (Nutrient Agar) (P 0.05), indicating that spores surviving severe heat treatments required nutrients not required by unheated spores. C. sporogenes spores counts of the extruded sample decreased after 1 and 2 weeks of storage under refrigeration conditions. The overall bacteriological quality of the extruded mixture of mechanically deboned turkey and white corn flour was excellent (0 spore/g in both Brewer Anaerobic Agar and Nutrient Agar)