Location: Processed Foods Research
Title: Effect of plant essential oils against foodborne pathogens Escherichia coli O157:H7 and Salmonella enterica in raw cookie dough Authors
Submitted to: Institute of Food Technologists
Publication Type: Abstract Only
Publication Acceptance Date: February 18, 2010
Publication Date: N/A
Technical Abstract: Cookie dough can be contaminated by raw ingredients, mishandling, package contamination, etc. Considering the recent outbreak of E. coli O157:H7 with commercial raw cookie dough, the ability of E. coli O157:H7 to survive in the raw cookie dough production and processing environments, it raised concerns about the potential for additional foodborne outbreaks. A feasible option to prevent further outbreaks is to incorporate a flavor-compatible antibacterial ingredient in cookie dough formulations to ensure adequate reduction of E. coli and Salmonella. Plant essential oils are a potentially useful source of antimicrobial compounds that can be incorporated into raw cookie dough. They can be added at relatively higher concentrations as they will partially evaporate during baking reducing their flavor impact in baked cookies. The major objective of the present study was to demonstrate that flavor-compatible plant essential oils can protect packaged raw cookie dough during cold storage without adverse effect on consumer preference. Cinnamon, allspice, clove bud, and nutmeg essential oils were incorporated into commercial cookie dough at 0-3% v/w levels. Following storage at 4°C overnight, cookie doughs with and without essential oil were inoculated with 5-6 logs of E. coli O157:H7 or Salmonella enterica. Inoculated cookie doughs were then sampled at 0, 1, 6 and 8 days after storage at 4°C to check for bacterial counts using selective media. Cinnamon oil showed the highest antimicrobial activity against the two pathogens among the four essential oils tested. The minimum concentrations needed to inactive E. coli O157:H7 and Salmonella enterica in the cookie dough were 0.5% and 0.1% cinnamon oil, respectively. Adding cinnamon oil at minimum concentrations did not change the consumer preference on baked cookies. These results demonstrated a potential practical application of plant essential oils as effective antibacterials against pathogenic bacteria in raw cookie dough.