Synergies of carvacrol and 1,8-cineole to inhibit bacteria associated with minimally processed vegetables.

Abstract This study assessed the occurrence of an enhancing inhibitory effect of the combined application of carvacrol and 1,8-cineole against bacteria associated with minimally processed vegetables using the determination of Fractional Inhibitory Concentration (FIC) index, time-kill assay in vegetable broth and application in vegetable matrices. Their effects, individually and in combination, on the sensory characteristics of the vegetables were also determined. Carvacrol and 1,8-cineole displayed Minimum Inhibitory Concentration (MIC) in a range of 0.6–2.5 and 5–20 μL/mL, respectively, against the organisms studied. FIC indices of the combined application of the compounds were 0.25 against Listeria monocytogenes , Aeromonas hydrophila and Pseudomonas fluorescens , suggesting a synergic interaction. Application of carvacrol and 1,8-cineole alone (MIC) or in a mixture (1/8 MIC + 1/8 MIC or 1/4 MIC + 1/4 MIC) in vegetable broth caused a significant decrease (p