Composição química e atividade antibacteriana do óleo essencial das folhas de Croton rhamnifolioides Pax & Hoffm / Chemical composition and antibacterial activity of essential oil of a Croton rhamnifolioides leaves Pax & Hoffm

O presente estudo descreve a composição química e a atividade antimicrobiana do óleo essencial das folhas de Croton rhamnifolioides Pax & Hoffm, uma planta aromática amplamente distribuída no Nordeste do Brasil e largamente utilizada na medicina popular. Cromatografia gasosa espectrometria de massa foi utilizada para determinar sua composição. Oito componentes foram identificados, sendo 1,8-cineol (46,32%) o composto majoritário, seguido por 1-felandreno (16,70%), p-cimeno (10,21%), sabineno (8,14%) e trans-cariofileno (4,81%). O óleo essencial apresentou atividade antibacteriana contra Aeromonas hydrophila, Escherichia coli, Listeria monocytogenes, Salmonella Enteritidis e Staphylococcus aureus com valores de concentração inibitória mínima (CIM) e concentração bactericida mínima (CBM) entre 2,5 - 20 ?L/mL e 5 - 40 ?L/mL, respectivamente. Além disso, o óleo essencial também afetou a viabilidade celular dessas bactérias. Os resultados sugerem a necessidade de estudos para estabelecer o uso potencial deste óleo essencial como antimicrobiano natural na indústria de alimentos.

This study describes the chemical composition and antimicrobial activity of an essential oil from the leaves of Croton rhamnifolioides Pax&Hoffm., an aromatic plant widely distributed in northeastern Brazil and commonly used in folk medicine. Eight components were identified: 1.8-cineole (46.32%) as the major compound, followed by 1-felandreno (16.70%), p-cymene (10.21%), sabinene (8.14%) and trans-caryophyllene (4.81%). The essential oil exhibited antibacterial activity against Aeromonas hydrophila, Escherichia coli, Listeria monocytogenes, Salmonella Enteritidis and Staphylococcus aureus, with minimum inhibitory concentrations and minimum bactericidal concentrations ranging from 2.5 to 20 and 5 to 40 ?L.mL1, respectively. In addition, the essential oil also affected the cellular viability of these bacteria. The results suggest the need for research to establish the potential uses of this essential oil as a natural antimicrobial in the food industry.

Composição química e atividade antibacteriana do óleo essencial das folhas de Croton rhamnifolioides Pax & Hoffm / Chemical composition and antibacterial activity of essential oil of a Croton rhamnifolioides leaves Pax & Hoffm

O presente estudo descreve a composição química e a atividade antimicrobiana do óleo essencial das folhas de Croton rhamnifolioides Pax & Hoffm, uma planta aromática amplamente distribuída no Nordeste do Brasil e largamente utilizada na medicina popular. Cromatografia gasosa espectrometria de massa foi utilizada para determinar sua composição. Oito componentes foram identificados, sendo 1,8-cineol (46,32%) o composto majoritário, seguido por 1-felandreno (16,70%), p-cimeno (10,21%), sabineno (8,14%) e trans-cariofileno (4,81%). O óleo essencial apresentou atividade antibacteriana contra Aeromonas hydrophila, Escherichia coli, Listeria monocytogenes, Salmonella Enteritidis e Staphylococcus aureus com valores de concentração inibitória mínima (CIM) e concentração bactericida mínima (CBM) entre 2,5 - 20 ?L/mL e 5 - 40 ?L/mL, respectivamente. Além disso, o óleo essencial também afetou a viabilidade celular dessas bactérias. Os resultados sugerem a necessidade de estudos para estabelecer o uso potencial deste óleo essencial como antimicrobiano natural na indústria de alimentos.

This study describes the chemical composition and antimicrobial activity of an essential oil from the leaves of Croton rhamnifolioides Pax&Hoffm., an aromatic plant widely distributed in northeastern Brazil and commonly used in folk medicine. Eight components were identified: 1.8-cineole (46.32%) as the major compound, followed by 1-felandreno (16.70%), p-cymene (10.21%), sabinene (8.14%) and trans-caryophyllene (4.81%). The essential oil exhibited antibacterial activity against Aeromonas hydrophila, Escherichia coli, Listeria monocytogenes, Salmonella Enteritidis and Staphylococcus aureus, with minimum inhibitory concentrations and minimum bactericidal concentrations ranging from 2.5 to 20 and 5 to 40 ?L.mL1, respectively. In addition, the essential oil also affected the cellular viability of these bacteria. The results suggest the need for research to establish the potential uses of this essential oil as a natural antimicrobial in the food industry.

The sensitivity of bacterial foodborne pathogens to Croton blanchetianus Baill essential oil

The aim of this study was to assess the activity of essential oil extracted from the leaves of C. blanchetianus Baill, popularly known as "marmeleiro", in inhibiting the growth and survival of pathogenic microorganisms in food by determining their survival in vitro and by observing the behaviour of Listeria monocytogenes inoculated into a food model (meat cubes) that was stored at refrigeration temperature (7 ± 1 ºC) for 4 days. The results indicated a bactericidal effect against Aeromonas hydrophila and Listeria monocytogenes and bacteriostatic action against Salmonella Enteritidis. A bacteriostatic effect on meat contaminated with L. monocytogenes was found for all concentrations of essential oils tested. These results showed that essential oil from the leaves of C. blanchetianus Baill represents an alternative source of potentially natural antimicrobial agents that may be used as a food preservative.

The sensitivity of bacterial foodborne pathogens to Croton blanchetianus Baill essential oil

The aim of this study was to assess the activity of essential oil extracted from the leaves of C. blanchetianus Baill, popularly known as "marmeleiro", in inhibiting the growth and survival of pathogenic microorganisms in food by determining their survival in vitro and by observing the behaviour of Listeria monocytogenes inoculated into a food model (meat cubes) that was stored at refrigeration temperature (7 ± 1 ºC) for 4 days. The results indicated a bactericidal effect against Aeromonas hydrophila and Listeria monocytogenes and bacteriostatic action against Salmonella Enteritidis. A bacteriostatic effect on meat contaminated with L. monocytogenes was found for all concentrations of essential oils tested. These results showed that essential oil from the leaves of C. blanchetianus Baill represents an alternative source of potentially natural antimicrobial agents that may be used as a food preservative.

Combination of Origanum vulgare L. essential oil and lactic acid to inhibit Staphylococcus aureus in meat broth and meat model

This study assessed the occurrence of an enhancing inhibitory effect of the combined application of Origanum vulgare L. essential oil and lactic acid against Staphylococcus aureus by the determination of Fractional Inhibitory Concentration (FIC) index and cell viability in meat broth and meat model. Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) of the oil was 0.6 and 1.25 µL.mL-1, respectively. Lactic acid showed MIC and MBC of 2.5 and 5µL.mL-1, respectively. FIC indices of the combined application of the oil and lactic acid were 0.5 showing a synergic interaction. The essential oil and lactic acid showed similar (p>0.05) anti-S. aureus effect in meat broth over 96 h of exposure. Treatment with essential oil or lactic acid presented a smaller anti-staphylococcal effect in meat in comparison to meat broth. No significant difference (p>0.05) was found for the microbial counts in meat treated with each antimicrobial alone or in mixture. These results could arise as an interesting approach for the improvement of food preservation using more natural procedures, considering the current demand of consumer and sensory quality of foods.

Combined application of origanum vulgare l. essential oil and acetic acid for controlling the growth of staphylococcus aureus in foods

This study evaluated the occurrence of an enhancing inhibitory effect of the combined application of Origanum vulgare L. essential oil and acetic acid against Staphylococcus aureus by the determination of Fractional Inhibitory Concentration (FIC) index and kill-time assay in nutrient broth, meat broth and in a food model (meat pieces). Acetic acid showed MIC and MFC of 0.6 and 1.25 µL.mL-1, respectively. For O. vulgare essential oil MIC and MBC were 1.25 and 2.5 µL.mL-1, respectively. FIC indexes of the mixture of essential oil and acetic acid at MIC x ½ were £ 1.0, showing an additive effect. No synergy was found at kill-time study. Anti-staphylococcal effect of the antimicrobials alone or in mixture (MIC x ½) was lower in meat than in nutrient and meat broths. The effective combination of essential oils and organic acids could appear as an attractive alternative for the food industry, as the doses to inhibit the microbial growth in foods can be lowered.

Este estudo avaliou a ocorrência de um efeito inibitório potencializado quando da aplicação combinada do óleo essencial de O. vulgare e ácido acético sobre Staphylococcus aureus através da determinação Concentração Inibitória Fracional (FIC) e de ensaios de tempo de morte em caldo nutriente, caldo base carne e em um modelo alimentar (pedaços de carne). O ácido acético mostrou um valor de CIM e CBM de 0,6 e 1,25 µL.mL-1, respectivamente. Estudos prévios encontraram valores de CIM e CBM para o óleo essencial de O. vulgare sobre as cepas teste de S. aureus de 1,25 e 1,5 µL.mL-1, respectivamente. Valores de índices de CIF da mistura do óleo essencial e ácido acético na concentração de CIM x ½ foram £ 1,0 caracterizando uma interação de adição. Nenhum efeito sinérgico foi encontrado nos ensaios de tempo de morte. O efeito anti-estafilocócico dos antimicrobianos isolados ou em combinação (CIM x ½) foi menor quando aplicado em carne em comparação a sua adição em caldo nutriente e caldo carne. A efetiva combinação de óleos essenciais e outros agentes preservativos pode ser reconhecida como uma alternativa promissora para a indústria de alimentos, podendo viabilizando a diminuição de doses de antimicrobianos aplicadas para inibir o crescimento microbiano em alimentos.