Inactivation of Listeria innocua in tryptic soy broth and poultry meat samples by high pressure processing

Abstract

Efficiency of high-pressure processing (HP) on the inactivation of Listeria innocua (ATTC 33090) suspensions in culture medium or inoculated into poultry samples was studied. First, the baroresistance of L. innocua in a tryptic soy broth suspension at a concentration of 108–109 Colony forming units (CFU)/ml was tested under varying cycles of pressurization in the range of 200–350 MPa (15 min total in each treatment) at 4 °C. In addition, the effect of HP on L. innocua inoculated in poultry (103 or 105/CFU/g) was examined. The results of these studies demonstrate the requisite treatment conditions and efficacy of pressure cycles in destroying L. innocua in poultry.