Modified Coring Tool Designs Reduce Iceberg Lettuce Cross-Contamination.

Area of Science:

• Food Safety
• Microbiology
• Agricultural Engineering

Background:

• Contaminated coring tools pose a risk of bacterial transfer to iceberg lettuce.
• Standard coring tools have design features that may facilitate bacterial contamination.

Purpose of the Study:

• To evaluate the efficiency of coring tool design modifications in reducing bacterial transfer to lettuce.
• To assess how different rinsing solutions affect bacterial retention on coring tools.

Main Methods:

• Corning tools with modified designs (e.g., removed welds, altered edges) were inoculated with Escherichia coli and used to core lettuce heads.
• Bioluminescent Salmonella Newport was used to evaluate bacterial transfer and spatial distribution on tools immersed in various solutions, observed via imaging.

Main Results:

• Removing the welded surface from coring tools reduced Escherichia coli transfer to 44%, a significant decrease compared to standard tools (91%).
• Coring tool design modifications showed reduced cross-contamination, especially in later uses.
• Immersion in solutions with lettuce extract resulted in greater Salmonella retention on tool surfaces compared to TSB or water.

Conclusions:

• Coring tool design modifications, particularly the removal of welded surfaces, are effective in minimizing bacterial cross-contamination of iceberg lettuce.
• Rinsing solutions containing organic matter, such as lettuce extract, can enhance bacterial retention on coring tools, potentially increasing cross-contamination risk.