Risk factors influencing the growth and survival of Salmonella on poultry products

Salmonella bacteria are commonly found in poultry carcasses and their presence after processing may lead to foodborne disease outbreaks. Consumption of frozen chicken products containing raw poultry has been recently identified as a risk factor for salmonellosis. Survival of the pathogen after freezing and frozen storage may lead to infection if the food product is insufficiently cooked when, for example, using a microwave oven.;In this dissertation, we have studied three scenarios that affect the risk of salmonellosis on poultry products: the effect of storage temperature on the growth of Salmonella on raw poultry, the survival of Salmonella during frozen storage in processed poultry products, and the efficacy of microwave cooking on the destruction of Salmonella in frozen chicken entrees. Our results show that (1) a model can be used to predict the growth of Salmonella on raw poultry as a function of storage temperature; (2) Salmonella are able to survive frozen storage on processed chicken products with structural injury as a consequence; (3) neither lipopolysaccharide nor porin defects hindered the survival of Salmonella during storage at -20°C; and (4) cooking of frozen entrees following the product's label instructions using a low-wattage (500W) microwave oven resulted in nonlethal heating profiles and Salmonella survival.;A quantitative microbial risk model was also developed in order to assess the risk of salmonellosis associated with consumption of raw, frozen chicken products cooked in low-wattage microwave ovens. A 2005 salmonellosis outbreak in Minnesota linked to raw, frozen chicken entrees was simulated 100 times using our model. Despite certain limitations in availability of data, model predictions (5-7 reported illnesses) were in close agreement with the actual outbreak outcome (4 reported illnesses). The risk assessment model developed may provide useful quantitative data relevant for risk management initiatives, ultimately aiming at controlling the risk of salmonellosis from raw, frozen chicken products.