<OL> <LI> Validate the Pathogen Modeling Program (PMP) for foods which present a relatively high risk of foodborne disease, including those recently ranked in risk assessments by the US Food & Drug Administration (FDA) and the US Department of Agriculture (USDA) Food Safety & Inspection Service (FSIS). <LI> Identify foods in which pathogens show significant deviations from models and develop new mathematical models, including those which address competitive microflora, the food matrix, functions of time, temperature, pathogen density and physiology and strain variation. <LI> Develop and validate process risk models for selected food process unit operations to estimate the behavior and distribution of pathogens for in-process foods.
APPROACH: Quantitative data on the effects of selected cultural parameters on the growth, survival, and virulence of foodborne pathogens will be collected in broth media and in representative foods, particularly meats, meat products, and poultry. Data will be appended into existing databases. Descriptive models will be developed from these results which will be incorporated into the existing Pathogen Modeling Program (PMP) and other risk assessment software. Software will be developed to permit linking a series of models that simulate a multi-step processing operation. Specific areas for research include understanding strain variation, lag phase duration, competitive flora, and the effects of different acidulants and humectants on model development.