title: Inhibitory activity of Syzygium aromaticum and Cymbopogon citratus (DC.) Stapf. essential oils against Listeria monocytogenes inoculated in bovine ground meat.
abstract: This research evaluated the antimicrobial effect of the clove (Syzygium aromaticum) and lemongrass (Cymbopogon citratus (DC.) Stapf.) essential oils (EOs) against Listeria monocytogenes ATCC 19117 growth added to bovine ground meat stored under refrigeration (5 ± 2 °C) for three days. The EOs, extracted by hydrodistillation and analyzed by gas chromatography-mass spectrometry (GC-MS), were tested in vitro using an agar well diffusion methodology for determination of Minimum Inhibitory Concentration (MIC). The MIC concentrations for both essential oils on culture tested of L. monocytogenes were 1.56%. The EOs concentrations applied in contaminated ground beef were 1.56, 3.125 and 6.25% (w/v) based on MIC levels and possible activity reductions by food constituents. The bacteria populations were significantly reduced (p ≤ 0.05) after one day of storage in ground meat samples treated with clove and lemongrass EOs at concentrations of 1.56%. There were no significant counts of L. monocytogenes in samples at the other concentrations of the two oils applied after the second day of storage. The sensory acceptability evaluation of the bovine ground meat samples treated with EOs showed that the addition at concentrations higher than 1.56% promote undesirable alterations of taste, odor and characteristic color. The application of EOs at low concentrations in food products can be used in combination with other preservation methods, such as refrigeration, to control pathogens and spoilage bacteria during shelf-life; which goes according to current market trends, where consumers are requesting natural products.
authors.affiliation: Universidade Federal de Lavras, Departamento de Ciência dos Alimentos, Laboratório de Microbiologia dos Alimentos, Lavras, MG, Brazil.
authors.forename: Thales Leandro Coutinho
authors.initials: TL
authors.lastname: de Oliveira
authors.forename: Maria
authors.initials: M
authors.lastname: das Graças Cardoso
authors.forename: Rodrigo
authors.initials: R
authors.lastname: de Araújo Soares
authors.forename: Eduardo Mendes
authors.initials: EM
authors.lastname: Ramos
authors.forename: Roberta Hilsdorf
authors.initials: RH
authors.lastname: Piccoli
authors.forename: Victor Maximiliano Reis
authors.initials: VM
authors.lastname: Tebaldi
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D002417:Cattle; D031743:Cymbopogon / Q000737:chemistry*; D005520:Food Preservatives / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D008401:Gas Chromatography-Mass Spectrometry; D008089:Listeria monocytogenes / Q000187:drug effects* / Q000254:growth & development; D008460:Meat / Q000382:microbiology*; D008826:Microbial Sensitivity Tests; D009822:Oils, Volatile / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D012034:Refrigeration; D027842:Syzygium / Q000737:chemistry*; D013696:Temperature
chemical_list: D000900:Anti-Bacterial Agents; D005520:Food Preservatives; D009822:Oils, Volatile
keywords: Listeria monocytogenes; clove; food safety; lemongrass; sensorial