Salmonella Research Today is a free monthly online journal that collates and summarizes the latest research about Salmonella, including details on salmonella typhimurium, food poisoning, infection, treatment.

Inactivation of Salmonella typhimurium DT 104 in UHT whole milk by high hydrostatic pressure.

Guan D, Chen H, Hoover DG

Department of Animal and Food Sciences, University of Delaware, Newark, DE 19716-2150, USA.

Cell suspensions of Salmonella typhimurium DT 104 in ultra-high temperature (UHT) whole milk were exposed to high hydrostatic pressure at 350, 400, 450, 500, 550, and 600 MPa at ambient temperature (ca. 21 degrees C). Tailing was observed in all survival curves, and sigmoidal survival curves were observed at relatively high pressure (500-600 MPa). Four modeling methods (linear and nonlinear including Weibull, modified Gompertz, and log-logistic models) were fitted to these data at 500, 550, and 600 MPa. Performances of the modeling methods were compared using mean square error (MSE). The linear regression model at these three pressure levels had a mean square error (MSE) of 1.260-2.263. Nonlinear regressions using Weibull, modified Gompertz, and log-logistic models had MSE values in the range of 0.334-0.764, 0.601-1.479, and 0.359-0.523, respectively. Modeling results indicated that first-order kinetics could not accurately describe pressure inactivation of S. typhimurium DT 104 in UHT milk; the log-logistic model produced the best fit to data.

Published 16 September 2005 in Int J Food Microbiol, 104(2): 145-53.
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