ARS | Publication request: THERMAL INACTIVATION OF SALMONELLA SPP. IN CHICKEN AS AFFECTED BY PH OF THE MEAT

Submitted to: International Journal of Food Science and Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: November 18, 2005
Publication Date: December 1, 2007
Citation: Juneja, V.K. 2007. Thermal inactivation of salmonella spp. in chicken as affected by ph of the meat. International Journal of Food Science and Technology. 42:1443-1448.

Interpretive Summary: Salmonella is a pathogen of major concern for the food industry since documentation of its association with several outbreaks of foodborne illness. Undercooked meat and poultry products are commonly implicated as transmission vehicles in these outbreaks. This emphasizes the need to better define and quantify the heat treatment given to these foods to provide an adequate degree of protection against survival of Salmonella. We determined that a heat treatment at 55C for 36.5 min and at 62.5C for 4.0 min would kill more than one million bacteria in chicken breast meat; the values in thigh meat ranged from 69.0 min at 55C to 5.0 min at 62.5C. The data reported 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 consumers and to the food industry and regulatory agencies to aid in the development of guidelines to ensure safety of the food supply.

Technical Abstract: Thermal inactivation of a four-strain mixture of Salmonella spp. was determined in chicken breast and thigh meat. Inoculated meat was packaged in bags which were completely immersed in a circulating water bath and held at 55, 57.5, 60, and 62.5C for predetermined lengths of time. When the surviving bacteria were enumerated on tryptic soy agar supplemented with 0.6% yeast extract and 1% pyruvate (non-selective medium), D-values in chicken breast meat were 6.08, 4.77, 3.00 and 0.66 min at 55, 57.5, 60, and 62.5C, respectively; the values in thigh meat ranged from 11.48 min at 55C to 0.84 min at 62.5C. As expected, the measured heat resistance was lower when the recovery medium was selective (xylose lysine deoxycholate agar). Thermal death time values from this study will assist food processors in designing HACCP plans to effectively eliminate Salmonella spp. in cooked chicken breast and thigh meat.