RESEARCH INTO THERMAL-RESISTANCE OF SALMONELLA-ENTERITIDIS PHAGOVAR-2IN THE CULINARY PREPARATIONS OF EGGS

Research focused on the kinetics of temperature rise and the thermal r esistance of Salmonella enteritidis phagovar 2 (S. enteritidis) in exp erimentally infected eggs during culinary preparation by boiling them in water (100 degrees C) and by frying in oil-seed oil (178-180 degree s C). The strain used in the tests was S. enteritidis phagovar 2 which , in the spring of 1994, caused alimentary infection of wide proportio ns due to the consumption of eggs. In the experimentally infected eggs the said bacteria multiplied during a 7-day incubation period, at a t emperature of 20 degrees C and 30 degrees C, from an initial 4.3x10(1) /ml to an infection Value of 1.3 x 10(6)/ml, that is to say, to 2.7x10 (6)/ml of yolk. Following thermal treatment at a temperature of 69 deg rees C, and after revitalization also at a temperature of up to 73 deg rees C, the researched S. enteritidis strain was isolated, but failed to survive thermal treatment either in vitro or in the artificially in fected eggs at a temperature of 75 degrees C. During the frying proces s in hot oil the invasive number of S. enteritidis in the yolks of exp erimentally infected eggs reduced insignificantly. Practically, this m eans that the safe and complete destruction of S. enteritidis can be a chieved only in hard-boiled eggs at a yolk temperature of 75 degrees C .