Title: Modeling the effects of temperature, sodium chloride and green tea and their interactions on the thermal inactivation of Listeria monocytogenes in turkey Authors
|Garcia-Davila, Jimena -|
|Lopez-Romero, Julio Cesar -|
|Pena-Ramos, Etna Aida -|
|Camou, Juan Pedro -|
|Valenzuela-Melendres, Martin -|
Submitted to: Food Microbiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: June 2, 2014
Publication Date: N/A
Interpretive Summary: Listeria monocytogenes continues to be a foodborne pathogen of significant public health concern. Therefore, there is a need to determine time and temperature required to destroy the pathogen in meat products in order to provide an adequate degree of protection against survival of this pathogen. We developed a predictive model for estimating heat treatment required for destruction of this pathogen in turkey products formulated with reduced salt. The model can be used to predict the time required at any temperature to kill a certain number of bacteria. This information will be of immediate use to the food industry and regulatory agencies to enhance the safety of ready-to-eat turkey products.
Technical Abstract: The interactive effects of heating temperature (55 – 65C), sodium chloride (NaCl, 0-2%), and green tea 60% polyphenol extract (GTPE, 0-3%) on heat resistance of a five-strain mixture of Listeria monocytogenes in ground turkey were determined. Thermal death times were quantified in bags submerged in a circulating water bath set at temperatures 55, 57, 60, 63, and 65C. The recovery medium was tryptic soy agar with added 0.6% yeast extract and 1% sodium pyruvate. The D-values obtained were analyzed by second order response surface regression for temperature, NaCl and GTPE. The data indicated that all three factors interacted to affect the inactivation of the pathogen. The D-values obtained for turkey with no NaCl or GTPE at 55, 57, 60, 63 and 65C were 36.32, 20.84, 13.15, 4.13 and 2.88 min, respectively. While NaCl exhibited a concentration-dependent protective effect against heat lethality on L. monocytogenes in turkey, addition of GTPE rendered the pathogen more sensitive to the lethal effect of heat. GTPE levels up to 1.5% interacted with NaCl and reduced the protective effect of NaCl on heat resistance of the pathogen. Food processors can use the predictive model to design an appropriate heat treatment for inactivating L. monocytogenes in cooked turkey products without adversely affecting the quality of the product.