Essential Oils Reduce Listeria Monocytogenes From Biofilm Surfaces And Fresh Catfish Fillets

The present work examines the antimicrobial efficacy of the essential oils of thyme, oregano and carvacrol against L. monocytogenes biofilms produced on stainless steel coupons and for control of L. monocytogenes growth on raw catfish fillets stored at 4°C for 10 days. At 0.5%, all three essential oils were highly effective in completely eliminating L. monocytogenes cells from stainless coupons within 24 h as compared to the untreated control yielding ~7 log CFU/cm2 L. monocytogenes. When catfish inoculated with L. monocytogenes were dipped for 30 min at 4°C in essential oil solutions of thyme and oregano at 1%, 2% and 5%, there were no significant reductions in L. monocytogenes counts on the fresh catfish fillets as compared to untreated control. For the same conditions, treatment with 2% carvacrol resulted in a complete reduction of 4 log CFU/g of L. monocytogenes counts from fresh catfish fillets