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United States Department of Agriculture

Agricultural Research Service

Research Project: DATA ACQUISITION AND MODELING FOR POULTRY FOOD SAFETY

Location: Residue Chemistry and Predictive Microbiology

Title: Growth of Salmonella Typhimurium DT104 at 30C is not affected by anatomical location on the chicken carcass

Author
item Oscar, Thomas

Submitted to: Journal of Food Protection
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: September 23, 2011
Publication Date: January 1, 2012
Citation: Oscar, T.P. 2012. Growth of Salmonella Typhimurium DT104 at 30C is not affected by anatomical location on the chicken carcass. Journal of Food Protection. 75(1)164-168.

Interpretive Summary: The chicken carcass is composed of three general types of meat: skin, white and dark. There are differences in chemical composition of these meats that are related to their function and location on the carcass. These chemical differences could affect growth of Salmonella during temperature abuse of chicken meat. Consequently, the present study was undertaken to determine whether or not chicken meat type affects growth of Salmonella during storage at a warm room temperature (i.e. 86F). Although there were differences in pH among meat types, these differences were not sufficient to affect growth of Salmonella at 86F. If this observation holds for other storage conditions then meat type does not need to be included as a variable in predictive models for chicken. This would save significant time and money for the predictive microbiologist.

Technical Abstract: Development of models for growth of Salmonella in the chicken food matrix is time consuming and expensive. The current study was undertaken to examine growth of Salmonella on different anatomical locations of the chicken carcass. The purpose was to determine whether or not anatomical location should be included as an independent variable in predictive models for chicken. Eleven anatomical locations were studied: skin (wing, breast, drumstick and thigh), meat surface (wing, breast, drumstick and thigh) and meat interior (breast, drumstick and thigh). Background microflora and pH and growth (lag time, LT; growth rate, GR; and time for a 3 log increase; t3) at 30C for a low inoculum size (0.92 log/portion) of Salmonella Typhimurium DT104 were examined. Four or six replicate storage trials were conducted per anatomical location (n = 46 growth curves). Portion sizes were 1.12 g for meat and 0.25 g for skin. A two-phase linear model was used to determine LT and GR. Effect of anatomical location on dependent variables was assessed by one-way analysis of variance. pH differed (P is less than 0.001) among anatomical locations with skin (6.86) is greater than dark meat (6.39) is greater than white meat (5.97). Background microflora (4.32 log/portion) was variable and not affected (P is greater than 0.05) by anatomical location. Likewise, LT (1.90 h), GR (0.648 log/h) and t3 (6.71 h) at 30C were not affected (P is greater than 0.05) by anatomical location. Although there were differences in pH among anatomical locations, these differences were not sufficient to affect growth of S. Typhimurium DT104 at 30C. If this observation holds for other storage conditions and strains then anatomical location does not need to be included as an independent variable in predictive models for chicken. This would save significant time and money for the predictive microbiologist.

Last Modified: 11/21/2014