P3-38 Validation of Cooking Instructions for the Reduction of Salmonella spp. and Listeria monocytogenes in Frozen French Fry Products

Wednesday, August 3, 2016
America's Center - St. Louis
Balasubrahmanyam Kottapalli, ConAgra Foods, Omaha, NE
Ashley Cunningham, ConAgra Foods, Omaha, NE
Edith Akins, ConAgra Foods, Omaha, NE
Todd Badgley, ConAgra Foods, Omaha, NE
Introduction: Frozen French fry products are typically considered not ready-to-eat, are sold in the foodservice markets with labelled cooking instructions, and are intended to be cooked before consumed. Currently, there is a lack of scientific literature demonstrating the lethality of labelled cooking instructions for French fry products.

Purpose: The purpose of this study was to evaluate if labelled cooking instructions for tater tots (a French fry product) are adequate to achieve an acceptable reduction in vegetative pathogens.

Methods: Frozen tater tots (not ready-to-eat) were obtained from a commercial facility. Samples were thawed, individually inoculated both on the surface and internally with multiple strains of Salmonella spp. and L. monocytogenes to achieve a target level of 108 CFU/g. Samples were fried directly from a frozen state in canola oil containing oil bath maintained at temperature of 350 ± 5°F (represents a worse-case scenario for cooking instructions). Frying times were between 0 and 120 seconds. Samples were analyzed for Salmonella spp. and L. monocytogenes using scientifically valid methods. The experiment was performed in triplicate. ANOVA analysis was performed to understand the inactivation kinetics of Salmonella spp. and L. monocytogenes during frying. The level of significance used was 5%.

Results: Both Salmonella and L. monocytogenes counts decreased with increase in frying time. An average of 4-log reduction (P<0.05) of Salmonella spp. and L. monocytogenes was achieved in tater tots when fried in the oil bath for 120 seconds (recommended instructions for cooking time is 120 seconds). 

Significance: The results of this study demonstrate that compliance with labelled cooking instructions can result in an acceptable reduction of vegetative pathogens in French fry products.  The data from this study can be used to perform scientific food safety risk assessments in the frozen French fry industry.