title: 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<0.05) in bacterial count over 24h. Mixtures of carvacrol and 1,8-cineole reduced (p<0.05) the inocula of all bacteria in vegetable broth and in experimentally inoculated fresh-cut vegetables. A similar efficacy was observed in the reduction of naturally occurring microorganisms in vegetables. Sensory evaluation revealed that the scores of the most-evaluated attributes fell between "like slightly" and "neither like nor dislike." The combination of carvacrol and 1,8-cineole at sub-inhibitory concentrations could constitute an interesting approach to sanitizing minimally processed vegetables.
authors.affiliation: Department of Nutrition, Health Sciences Center, Federal University of Pernambuco, Recife, Brazil. evandroleitesouza@ccs.ufpb.br
authors.forename: Jossana Pereira
authors.initials: JP
authors.lastname: de Sousa
authors.forename: Geíza Alves
authors.initials: GA
authors.lastname: de Azerêdo
authors.forename: Rayanne
authors.initials: R
authors.lastname: de Araújo Torres
authors.forename: Margarida Angélica
authors.initials: MA
authors.lastname: da Silva Vasconcelos
authors.forename: Maria Lúcia
authors.initials: ML
authors.lastname: da Conceição
authors.forename: Evandro Leite
authors.initials: EL
authors.lastname: de Souza
mesh_terms: D016980:Aeromonas hydrophila / Q000187:drug effects; D000890:Anti-Infective Agents / Q000494:pharmacology*; D001419:Bacteria / Q000187:drug effects*; D015169:Colony Count, Microbial; D003511:Cyclohexanols / Q000494:pharmacology*; D000081007:Cymenes; D003666:Decontamination; D004338:Drug Combinations; D004357:Drug Synergism; D000077591:Eucalyptol; D005511:Food Handling; D005516:Food Microbiology; D008089:Listeria monocytogenes / Q000187:drug effects; D008826:Microbial Sensitivity Tests; D039821:Monoterpenes / Q000494:pharmacology*; D011551:Pseudomonas fluorescens / Q000187:drug effects; D014675:Vegetables / Q000382:microbiology*
chemical_list: D000890:Anti-Infective Agents; D003511:Cyclohexanols; D000081007:Cymenes; D004338:Drug Combinations; D039821:Monoterpenes; C073316:carvacrol; D000077591:Eucalyptol