Thermal inactivation of Listeria monocytogenes in different shaped traditional meatballs (İnegöl and Kasap)

In this study thermal inactivation of Listeria monocytogenes in meatballs that have two different geometrical figures were investigated. In the first part of the study, cooking parameters were obtained from restaurants to assess if the field conditions were sufficient to provide necessary inactivation (5-log reduction). Cooking parameters of the study were planned based on the data obtained from this part of the study. Two of the frequently consumed meatball types İnegöl and Kasap were chosen for the inactivation studies. Meatballs were inoculated with L. monocytogenes around 7 log cfu/g. The lowest temperature and shortest time parameters obtained from the restaurants were tested and since these parameters was not sufficient for 5 log inactivation of L. monocytogenes, the necessary cooking parameters were determined with a cooking study based on central temperatures of meatballs. Two different grill surface temperatures were used (170 and 180 °C) and sampling was made when the central temperature of meatballs reached the target temperatures. Results of the study show that cooking at 85°C and 90°C (central temperature) for İnegöl and 80°C for kasap meatball is sufficient to achieve 5-log inactivation principle set by FDA. Results also show that the general cooking principle (heating central temperature to 71.1°C) was not applicable for 5-log inactivation in meatballs that are frequently consumed in our country and the insufficient cooking parameters used by restaurants possess a food safety risk.