Abstract

The objective of this study was to evaluate the ability of the Weibull distribution to predict the inactivation of Salmonella in three meat products cooked under isothermal and non-isothermal conditions. Ground turkey thigh (5.09% fat, pH 6.45), turkey breast (0.47% fat, pH 6.04) and pork (17.04% fat, pH 6.36) were inoculated with an 8 strain Salmonella cocktail. The meat was cooked isothermally at 50, 54, 58, 62 and 66ºC, and non-isothermally at two heating rates (5 or 10 ºC/min) to 54, 60 and 66 ºC. Surviving Salmonella were enumerated at intervals during the cooking process. Isothermal survival curves were described by the Weibull distribution, log S (t) = -b (T) t^n(T), and its simplified form as a linear equation (n=1). Nonlinearity was observed in Salmonella survival curves. The Weibull distribution described pathogen inactivation better than its simplified linear form for all isothermal trials. The b and n parameters from isothermal data were used to predict the non-isothermal survival curves. Piecewise cubic hermite interpolating polynomial was used to estimate b and n in the non-isothermal program. At 54 and 66 ºC, the Weibull model well predicted the non-isothermal Salmonella survival curves for all meats. The model over-predicted the destruction of Salmonella in three meats at 60 ºC for both heating rates. The accurate prediction of Salmonella destruction at 66 ºC was at a higher temperature than the range of validity reported in the literature.

Submitted: March 12, 2009 · Accepted: June 18, 2009 · Published: July 6, 2009

Recommended Citation

Takhar, Pawan S.; Head, Kari L.; Hendrix, Kathleen M.; and Smith, Denise M. (2009) "Predictive Modeling of Salmonella Species Inactivation in Ground Pork and Turkey during Cooking," International Journal of Food Engineering: Vol. 5 : Iss. 2, Article 11.
DOI: 10.2202/1556-3758.1642
Available at: http://www.bepress.com/ijfe/vol5/iss2/art11