Purpose: The purpose of this study was to evaluate cooling time and combinations of cooling techniques to determine their impact on Escherichia coli (E. coli) populations in a chili product.
Methods: Chili was prepared following a recipe to meet school nutrition standards and poured into commercial serving pans to 2 and 3 inch depths, then cooled to 135-140°F before inoculation with E. coli (target concentration of 104 CFU/g). Filled pans were stored in a commercial walk-in freezer (-20°C) or placed in ice water baths in a commercial walk-in refrigerator (4°C). All pans were stored uncovered or covered, with or without an air gap and temperature of the food product was monitored every minute for 24 h. Samples were plated onto MacConkey agar at 0, 4, 8, 12, and 24 h, and incubated for 18-24 hours to enumerate E. coli populations.
Results: No statistically significant difference (P>0.05) in E. coli population was observed for time, cover, treatment (refrigerator vs. freezer) or depth. No statistically significant interactions were observed (P>0.05). These data indicate that all cooling treatments evaluated were effective at controlling E. coli populations in chili.
Significance: Young children are an at-risk population for severe illness and life-threatening complications from foodborne pathogens. Therefore, it is necessary to conduct research to discover and evaluate cooling methods that are effective at controlling foodborne pathogens in school lunch programs and translate these data into educational materials and trainings for food service personnel.