Bio‐sanitation treatment using essential oils against <i>E. coli</i> O157:H7 on fresh lettuce

Abstract

ABSTRACT The study was undertaken to develop an effective bio‐sanitation treatment using essential oils for the highly perishable leafy vegetable lettuce. The combination of thyme oil and tea tree oil mixed together had a significantly higher total phenolic content as well as higher antioxidant scavenging activity than other single oils or oil mixtures. Lettuce inoculated with Escherichia coli O157:H7 showed significantly reduced population counts in the presence of the sanitation treatment of a combination of thyme + tea tree oil applied by dipping at 0.75% + 0.75% or 1.5% + 1.5% concentrations compared to commercial sodium hypochlorite (200 mg/L NaOCl) washing after 5 days shelf life at 10°C. These results indicate that thyme + tea tree oil dipping treatment could be used to control E. coli O157:H7 contamination in lettuce as an alternative to NaOCl.