RT Journal Article
T1 Indirect measurement of the lag time distribution of single cells of Listeria innocua in food
A1 D'Arrigo, Matilde
A1 García De Fernando Minguillón, Gonzalo Doroteo
A1 Velasco De Diego, Raquel
A1 Ordóñez Pereda, Juan Antonio
A1 George, Susan M.
A1 Pin Arias, Carmen
AB The distribution of log counts at a given time during the exponential growth phase of Listeria innocua measured in food samples inoculated with one cell each was applied to estimate the distribution of the single-cell lag times. Three replicate experiments in broth showed that the distribution of the log counts is a linear mapping of the distribution of the detection times measured by optical density. The detection time distribution reflects the lag time distribution but is shifted in time. The log count distribution was applied to estimate the distributions of the lag times in a liquid dairy product and in liver pate´ after different heat treatments. Two batches of ca. 100 samples of the dairy product were inoculated and heated at 55°C for 45 min or at 62°C for 2 min, and an unheated batch was incubated at 4°C. The final concentration of surviving bacteria was ca. 1 cell per sample. The unheated cells showed the shortest lag times with the smallest variance. The mean and the variance of the lag times of the surviving cells at 62°C were greater than those of the cells treated at 55°C. Three batches of pate´ samples were heated at 55°C for 25 min, 62°C for 81 s, or 65°C for 20 s. A control batch was inoculated but not heated. All pate´ samples were incubated at 15°C. The distribution of the lag times of the cells heated at 55°C was not significantly different from that of the unheated cells. However, at the higher temperatures, 62°C and 65°C, the lag duration was longer and its variance greater
PB American Society for Microbiology
SN 0099-2240
YR 2006
FD 2006
LK https://hdl.handle.net/20.500.14352/96764
UL https://hdl.handle.net/20.500.14352/96764
LA eng
NO D’Arrigo M, García de Fernando G, Velasco de Diego R, Ordoñez JA, George SM, Pin, C. Indirect Measurement of the Lag Time Distribution of Single Cells of Listeria innocua in Food. Appl Environ Microbiol.2006 Apr;72(4):2533–38
NO Comisión Interministerial de Ciencia y Tecnología (España)
DS Docta Complutense
RD 21 abr 2025