Heat resistance of Listeria monocytogenes.
Two methods were used to study the thermal resistance of Listeria monocytogenes. The D60 degrees C values ranged from 1.3 to 6.5 s in a open vessel. D72 degrees C varied from 0.06 to 1.5 s and z from 3.1 to 6.5 K (38 strains) in capillary tubes. Therefore a conventional pasteurization process of 15 s at 72 degrees C could assure 10 to 250 decimal reductions, depending on the strain. Six days enrichment at 4 degrees C in milk prior to incubation at 37 degrees C did not show any influence on measured heat resistance (4 strains). A significant difference of thermal resistance among strains according to their serotype was noted: strains belonging to serogroup 1 were more heat resistant than those belonging to serogroup 4.
Lemaire
V
V
Microbiology Laboratory, Faculty of Medicine, Tours, France.
Cerf
O
O
Audurier
A
A
D006358:Hot Temperature; D008089:Listeria monocytogenes / Q000502:physiology*; D013997:Time Factors