The homogenate was serially diluted in BPW, plated on BHI agar plates (Difco, BD Diagnostic Systems, Sparks, MD, USA), and then incubated anaerobically overnight at 37 C. Results were expressed as DR values (DR ¼ log10[final count/g meat] log10[initial count/g meat]), where initial counts refer to counts from the heat-activated sample prior to the incubation for germination at 55 C.