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

Abstract

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

Synergistic antifungal effects of thyme essential oil and Lactobacillus plantarum cell-free supernatant against Penicillium spp. and in situ effects

“…The synergistic antifungal effects of thyme essential oil and LCFS are explained though the interactions between essential oil and its phenolic compounds with lactic acids as proposed earlier by Barros et al (2012). Lactic acid in LCFS provides the acidic environment that increases the hydrophobicity of essential oils.…”

“…The synergistic antifungal effects between essential oil and LCFS were evaluated by using FIC index by following the method of Barros, Conceição, Gomes Neto, Costa, and Souza (), with slight modifications. The tested combinations (thyme essential oil + LCFS) were; ½ MIC + ½ MIC, ½ MIC + ¼ MIC, ½ MIC + ⅛ MIC, ¼ MIC + ½ MIC, ¼ MIC + ¼ MIC, ¼ MIC + ⅛ MIC, ⅛ MIC + ½ MIC, ⅛ MIC + ¼ MIC, and ⅛ MIC + ⅛ MIC.…”

“…The synergistic antifungal effects between essential oil and LCFS were evaluated by using FIC index by following the method of Barros, Conceição, Gomes Neto, Costa, and Souza (2012), with slight modifications. The tested combinations (thyme essential…”

“…Furthermore, the phenolic compounds present in the essential oil are known to cause sub-lethal injury to the cell membranes through the disruption of proton motive force (H 1 ) and the interference of cellular energy production. This injury makes the cells more vulnerable to the acidic environment caused by lactic acids and organic acids present in LCFS (Barros et al, 2012). The degree of degradation increased with increase in the concentration of the mixture applied, suggesting that the effect was derived from the addition of the mixture.…”

The Anti-Staphylococcus aureus Effect of Combined Echinophora platyloba Essential Oil and Liquid Smoke in Beef

“…For instance, to inhibit spoilage in food matrices, the addition of high concentration of antimicrobial agents is required, which oft en exceeds the acceptable fl avour threshold of consumers (5).…”