Abstract
The plant‐derived essential oil component eugenol (1.0% wt/vol), free or loaded into surfactant micelles constructed of sodium dodecyl sulfate (SDS; 1.0% wt/vol), 200 ppm free chlorine (hypochlorous acid [HOCl]; pH 7.0), and sterile distilled water were evaluated for their ability to reduce Salmonella Saintpaul and Escherichia coli O157:H7 on skin surface samples of Roma tomatoes. Samples were treated and then stored aerobically for up to 10 days. All samples were initially stored at 5 °C; one set of samples was shifted to 15 °C after 5 days of storage to simulate temperature abuse during postharvest handling. Encapsulated and free eugenol, HOCl, and empty SDS micelles reduced pathogens to nondetectable counts (detection limit: 0.5 log10 cfu/cm2) during refrigerated storage (p ≥ .05). Conversely, during temperature abuse storage (15 °C), only free and micelle‐loaded eugenol consistently reduced pathogens to nondetection. Eugenol‐loaded micelles can be used to decontaminate harvested tomatoes from enteric bacterial pathogens.
Practical applications
Tomatoes may be consumed raw and have been repeatedly implicated in the occurrence of human foodborne disease. Washing of tomatoes with novel antimicrobial interventions that increase the dispersion of antimicrobials over the surface of the tomato should result in greater reduction of microbial foodborne pathogens through enhanced contact of antimicrobial with pathogen. Application of surfactant micelle‐entrapped eugenol onto tomato surfaces reduced Salmonella Saintpaul and Escherichia coli O157:H7 to nondetection during refrigerated (5 °C) and temperature abuse (15 °C) storage. Micelle‐loaded eugenol reduced numbers of aerobic bacteria, Enterobacteriaceae, and fungi to nondetection during temperature abuse storage.
