Thermal inactivation of Listeria monocytogenes and Yersinia enterocolitica in minced beef under laboratory conditions and in sous-vide prepared minced and solid beef cooked in a commercial retort.
D-values were obtained for Listeria monocytogenes and Yersinia enterocolitica at 50, 55 and 60 degrees C in vacuum-packed minced beef samples heated in a laboratory water-bath. The experiment was repeated using vacutainers, which allowed heating of the beef to the desired temperature before inoculation. D-values of between 0.15 and 36.1 min were obtained for L. monocytogenes. Pre-heating the beef samples significantly affected (P < 0.05) the D60 value only. D-values for Y. enterocolitica ranged from 0.55 to 21.2 min and all the D-values were significantly different (P < 0.05) after pre-heating. In general, the D-values obtained for core inoculated solid beef samples were significantly higher (P < 0.05) than those generated in minced beef when heated in a Barriquand Steriflow commercial retort.
Bolton
D J
DJ
The National Food Centre, Teagasc, Dunsinea, Castleknock, Dublin 15, Ireland. d.bolton@nfc.teagasc.ie
McMahon
C M
CM
Doherty
A M
AM
Sheridan
J J
JJ
McDowell
D A
DA
Blair
I S
IS
Harrington
D
D
D000818:Animals; D002417:Cattle; D006361:Heating; D006863:Hydrogen-Ion Concentration; D008089:Listeria monocytogenes / Q000254:growth & development*; D008460:Meat / Q000382:microbiology*; D015008:Yersinia enterocolitica / Q000254:growth & development*