Rayssa Julliane de Carvalho

Inhibition of Staphylococcus aureus cocktail using the synergies of oregano and rosemary essential oils or carvacrol and 1,8-cineole.

This study assessed the inhibitory effects of the essential oils (EOs) from Origanum vulgare L. (OVEO) and Rosmarinus officinalis L. (ROEO), as well as of the its majority individual constituents (ICs) carvacrol (CAR) and 1,8-cineole (CIN), respectively, combined at subinhibitory concentrations against a cocktail of Staphylococcus aureus. The Minimum inhibitory Concentration (MIC) of both OVEO and CAR against S. aureus cocktail was 1.25 μL/mL, while for ROEO and CIN the MIC value was 10 μL/mL. The Fractional Inhibitory Concentration Index of the combined EOs or ICs was ≤0.5 indicating a synergic interaction. The incorporation of OVEO and ROEO or CAR and CIN at different combinations in cheese and meat broths caused a decrease (p ≤ 0.05) of initial counts of S. aureus. Combined application of 1/8 MIC OVEO and 1/4 MIC ROEO or 1/4 MIC CAR and 1/4 MIC CIN in meat and cheese samples reduced (p ≤ 0.05) the viable cells counts and caused morphological changes in S. aureus cells, such as cell shrinkage and appearance of blebbing-like structures on cell surfaces. However, in cheese and meat samples the decrease in viable cell counts was smaller (p ≤ 0.05) than that observed in cheese and meat broths. These findings reinforce the potential of the use of OVEO and ROEO or CAR and CIN in combination to control S. aureus in cheese and meat matrices.

Effects of the Essential Oil from Origanum vulgare L. on Survival of Pathogenic Bacteria and Starter Lactic Acid Bacteria in Semihard Cheese Broth and Slurry

This study assessed the inhibitory effects of the essential oil from Origanum vulgare L. (OVEO) on Staphylococcus aureus, Listeria monocytogenes, and a mesophilic starter coculture composed of lactic acid bacteria (Lactococcus lactis subsp. lactis and L. lactis subsp. cremoris) in Brazilian coalho cheese systems. The MIC of OVEO was 2.5 μl/ml against both S. aureus and L. monocytogenes and 0.6 μl/ml against the tested starter coculture. In cheese broth containing OVEO at 0.6 μl/ml, no decrease in viable cell counts (VCC) of both pathogenic bacteria was observed, whereas the initial VCC of the starter coculture decreased approximately 1.0 log CFU/ml after 24 h of exposure at 10°C. OVEO at 1.25 and 2.5 μl/ml caused reductions of up to 2.0 and 2.5 log CFU/ml in S. aureus and L. monocytogenes, respectively, after 24 h of exposure in cheese broth. At these same concentrations, OVEO caused a greater decrease of initial VCC of the starter coculture following 4 h of exposure. Higher concentrations of OVEO were required to decrease the VCC of all target bacteria in semisolid coalho cheese slurry compared with cheese broth. The VCC of Lactococcus spp. in coalho cheese slurry containing OVEO were always lower than those of pathogenic bacteria under the same conditions. These results suggest that the concentrations of OVEO used to control pathogenic bacteria in semihard cheese should be carefully evaluated because of its inhibitory effects on the growth of starter lactic acid cultures used during the production of the product.

Efficacy of the Application of A Coating Composed of Chitosan and Mentha Piperita Essential Oil To Control of Post-Harvest Fungal Pathogens in Tomatoes (Lycopersicum Esculentum)

Ingrid Conceicao Dantas Guerra, Rayssa Julliane de Carvalho, Estefânia Fernandes Garcia, Marta Suely Madruga, Priscila Dinah Lima Oliveira, Maria Lucia da Conceicao, Evandro Leite de Souza. Efficacy of the Application of A Coating Composed of Chitosan and Mentha piperita Essential Oil To Control of Post-Harvest Fungal Pathogens in Tomatoes (Lycopersicum esculentum). In: Anais do 12o Congresso Latinoamericano de Microbiologia e Higiene de Alimentos MICROAL 2014 [= Blucher Food Science Proceedings, num.1, vol.1]. Sao Paulo: Editora Blucher, 2014. DOI 10.5151/foodsci-microal-302 Efficacy of the Application of A Coating Composed of Chitosan and Mentha piperita Essential Oil To Control of Post-Harvest Fungal Pathogens in Tomatoes (Lycopersicum esculentum)

Antimicrobial Activity of the Origanum Vulgare L. Essential Oil Against Pathogenic and Starter Bacteria Species Related To Brazilian Semi-Hard Cheese (Coalho)

Geany Targino de Souza, Rayssa Julliane de Carvalho, Neyrijane Targino de Souza, Jessica Bezerra dos Santos Rodrigues, Danilo Elias Xavier, Evandro Leite de Souza, Marciane Magnani. Antimicrobial Activity of the Origanum vulgare L. Essential Oil Against Pathogenic and Starter Bacteria Species Related To Brazilian Semi-Hard Cheese (Coalho). In: Anais do 12o Congresso Latinoamericano de Microbiologia e Higiene de Alimentos MICROAL 2014 [= Blucher Food Science Proceedings, num.1, vol.1]. Sao Paulo: Editora Blucher, 2014. DOI 10.5151/foodsci-microal-325 Antimicrobial Activity of the Origanum vulgare L. Essential Oil Against Pathogenic and Starter Bacteria Species Related To Brazilian Semi-Hard Cheese (Coalho)

Eficácia de Ácidos Orgânicos Na Sobrevivência da Escherichia Coli em Caldo Vegetal de Alface (Lactuca Sativa L.)

Geany Targino de Souza, Jessica Bezerra dos Santos Rodrigues, Rayssa Julliane de Carvalho, Neyrijane Targino de Souza, Kataryne Arabe Rima de Oliveira, Rilavia Almeida Lima, Evandro Leite de Souza, Maria Lucia da Conceicao. Eficacia de Acidos Orgânicos na Sobrevivencia da Escherichia coli em Caldo Vegetal de Alface (Lactuca sativa L.). In: Anais do 12o Congresso Latinoamericano de Microbiologia e Higiene de Alimentos MICROAL 2014 [= Blucher Food Science Proceedings, num.1, vol.1]. Sao Paulo: Editora Blucher, 2014. DOI 10.5151/foodsci-microal-340 Eficacia de Acidos Orgânicos na Sobrevivencia da Escherichia coli em Caldo Vegetal de Alface (Lactuca sativa L.)