P1-153 Development of a QMRA Model for Listeria monocytogenes on Frankfurters to Determine Risk-based Critical Control Points at the Processing Level

Monday, July 23, 2012
Exhibit Hall (Rhode Island Convention Center)
Elizabeth Williams, University of Maryland, College Park, MD
Robert Buchanan, University of Maryland, College Park , MD
Introduction: Quantitative Microbial Risk Assessment (QMRA) is being increasingly used to provide sound food safety advice to risk managers. However, its integration into the primary risk management system for food safety, HACCP, has been limited.  The ability to link the stringency of HACCP programs to food safety outcomes is critical to ultimately developing risk-based food safety systems. 

Purpose: The overall goal is to develop a means to allow food producers to more effectively link HACCP plans to food safety risk management metrics. The specific objectives include developing a facility-specific product-pathogen risk assessment model for frankfurters and determining if sensitivity analysis can be used to identify risk-based Critical Control Points.

Methods: A six-module risk assessment model for Listeria monocytogenes in frankfurters was developed in Excel using @Risk. The exposure assessment for frankfurters processing was divided into six modules: Ingredients, Raw Product Processing, Cooked Product Processing, Distribution and Marketing, and Consumer.  The output of the exposure model was then linked to the Dose Response Module based on the FAO/WHO L. monocytogenesmodel. Risk distributions were then simulated (10,000-to-1,000,000 iterations), and subsequently analyzed via sensitivity and “what-if” scenario analyses.

Results: The contamination level of Listeria monocytogenesat the final storage level at the processing facility was found to be similar to that obtained from the reference data. The sensitivity analysis suggested that besides thermal processing, two additional CCPs included the use of gloves to remove non-compliant products prior to packaging and the time of final storage as the critical factors in the cooked product processing module.

Significance: This study provides a quantitative risk-based approach to determine critical control points which could be used for the implementation of hazard mitigation strategies and other food safety risk analysis decision making. This work provides a pathway to link safe food production with public health.