Purpose: A Monte Carlo risk assessment was performed in order to assess the risk of salmonellosis presented by commercial raw peanuts used for production of peanut butter, and the degree to which it would be controlled by application of intervention processes validated to defined performance standards.
Methods: The Monte Carlo risk assessment was performed using available Salmonella prevalence and level data for raw runner peanuts, the primary feedstock for peanut butter production. The impact of microbial interventions was computed, and the risk of illness from any residual Salmonella was estimated using two dose response models, one commonly cited in Salmonella risk assessments and one designed to better model Salmonella infectivity in low water activity foods.
Results: In the absence of an intervention it was estimated that an arithmetic average of 244 individuals per billion servings of raw peanuts would experience salmonellosis. In the absence of an episodic contamination event a roasting process validated to achieve a reduction of 3 logs or more would be sufficient to produce very low risk, defined as less than 1 hospitalization per billion servings of shelled runner peanut products. Under a worst case scenario in which Salmonella is amplified in a railcar of peanuts due to the presence of moisture from condensation, introducing a "slug" of contamination to a roasting process, the reduction required to produce a very low risk product would increase to 4 logs.
Significance: The results of the risk assessment support a conclusion that raw runner peanuts may be converted to a very low risk food item by application of a validated microbial intervention of less than 5 logs.