Abstract Objective Evaluate autonomic function and low-grade inflammation and characterize the correlation between these variables in schoolchildren with obesity living in the Brazilian northeast region. Methods 84 children with obesity and 41 with normal weight were included in this cross-sectional study. Anthropometry, body composition, blood pressure (BP), inflammatory biomarkers, and heart rate variability (HRV) indexes were analyzed in children aged 7 to 11 years. Results children with obesity had increased systolic (p= 0.0017) and diastolic (p= 0.0131) BP and heart rate (p= 0.0022). The children with obesity displayed significantly lower SDNN, RMSSD, NN50, HF (ms), HF (nu), SD1, SD2, and higher LF (ms), LF (nu), LF/HF, SD1/SD2, DFA-α1, and DFA-α2, compared to normal weight. A lower and higher capacity for producing IL-10 (p= 0.039) and IL-2 (p= 0.009), respectively, were found in children with obesity compared to children with normal weight. Although IL-2, IL-4 and IL17A did not correlate with HRV parameters, IL-6 was positively correlated with SDNN, LF (ms) and SD2, TNF-α was positively correlated with LF/HF and SD1/SD2 ratio, and IFN-γ was positively correlated with SDNN, RMMSSD, NN50, LF (ms), HF (ms), SD1, and SD2. Conclusions The findings suggest that children with obesity have impaired autonomic function and systemic low-grade inflammation compared to children within the normal weight range, the inflammatory biomarkers were correlated with HRV parameters in schoolchildren living in the northeastern region of Brazil. lowgrade low grade 8 4 crosssectional cross sectional study Anthropometry composition BP, , (BP) (HRV 1 years p= p (p 0.0017 00017 0 0017 0.0131 00131 0131 0.0022. 00022 0.0022 . 0022 0.0022) SDNN RMSSD NN50 NN ms, ms nu, nu (nu) SD1 SD SD2 LFHF SD1SD2 SDSD DFAα1, DFAα1 DFAα DFA α1, α1 α DFA-α1 DFAα2, DFAα2 α2, α2 DFA-α2 IL10 IL 10 IL-1 0.039 0039 039 IL2 2 IL- 0.009, 0009 0.009 009 0.009) respectively IL2, 2, IL4 ILA IL6 6 (ms TNFα TNF SD1/SD ratio IFNγ IFN γ RMMSSD range Brazil (BP 0.001 0001 001 0.013 0013 013 0002 0.002 002 NN5 (nu SD1SD DFA-α IL1 0.03 003 03 000 0.00 00 0.01 01 0.0 0.

Origanum vulgare L. (OVEO) essential oil has been considered a candidate antimicrobial for use in food conservation systems. However, studies on the influence of concomitant variations of different food components or physicochemical parameters on the antibacterial properties of OVEO are scarce. This study assessed the influence of concomitant variations in amounts of proteins - PTN (4.0, 6.0 or 8.0 g/100 mL) and lipids - LIP (3.75, 5.0 or 6.25 g/100 mL) and pH values (5.0, 5.5 or 6.0) in cultivation medium on the inhibitory effects of OVEO against Escherichia coli (EC) and Salmonella Typhimurium (ST). Lowest minimum inhibitory concentration values of OVEO against EC and ST were observed in media with the highest LIP amounts regardless the PTN amount and pH value. In absorbance based microtiter plate assay (MPA), for both EC and ST, OVEO caused the lowest Grmax values in medium containing the highest LIP and PTN amounts and lowest pH value. Highest Grmax values for EC and ST were observed in medium containing the lowest LIP and PTN amount and highest pH value. Grmax values estimated from viable counts of EC and ST in tested media with OVEO confirmed bacterial growth behavior similar to that observed in MPA. Overall, the LIP amount in media was as the most influential factor to enhance the antibacterial effects of OVEO. These results indicate that the concomitant influence of LIP and PTN amounts and pH values on the antibacterial effects of OVEO should be considered for optimizing its antimicrobial efficacy in foods.

Enterotoxigenic Staphylococcus aureus strains that were isolated from foods were investigated for their ability to develop direct-tolerance and cross-tolerance to sodium chloride (NaCl), potassium chloride (KCl), lactic acid (LA) and acetic acid (AA) after habituation in sublethal amounts (1/2 of the minimum inhibitory concentration - 1/2 MIC and 1/4 of the minimum inhibitory concentration - 1/4 MIC) of Origanum vulgare L. essential oil (OVEO). The habituation of S. aureus to 1/2 MIC and 1/4 MIC of OVEO did not induce direct-tolerance or cross-tolerance in the tested strains, as assessed by modulation of MIC values. Otherwise, exposing the strains to OVEO at sublethal concentrations maintained or increased the sensitivity of the cells to the tested stressing agents because the MIC values of OVEO, NaCl, KCl, LA and AA against the cells that were previously habituated to OVEO remained the same or decreased when compared with non-habituated cells. These data indicate that OVEO does not have an inductive effect on the acquisition of direct-tolerance or cross-tolerance in the tested enterotoxigenic strains of S. aureus to antimicrobial agents that are typically used in food preservation.

This study assessed the capacity of adhesion, the detachment kinetic and the biofilm formation by Staphylococcus aureus isolated from food services on stainless steel and polypropylene surfaces (2 x 2 cm) when cultivated in a meat-based broth at 28 and 7 ºC. It was also to study the efficacy of the sanitizers sodium hypochlorite (250 mg/L) and peracetic acid (30 mg/L) in inactivating the bacterial cells in the preformed biofilm. S. aureus strains adhered in high numbers regardless the assayed surface kind and incubation temperature over 72 h. Cells detachment of surfaces revealed high persistence over the incubation period. Number of cells needed for biofilm formation was noted at all experimental systems already after 3 days. Peracetic acid and sodium hypochlorite were not efficient in completely removing the cells of S. aureus adhered on polypropylene and stainless steel surfaces. From these results, the assayed strains revealed high capacity to adhere and form biofilm on polypropylene and stainless steel surfaces under different growth conditions. Moreover, the cells in biofilm matrix were resistant for total removal when submitted to the exposure to sanitizers.

Objetivou-se com este estudo verificar as condições higiênico-sanitárias e criar um plano de Análise de Perigos e Pontos Críticos de Controle (APPCC) para implantação em duas indústrias de processamento de lagosta no Estado de Pernambuco, Brasil. As indústrias estudadas processam lagosta inteira congelada, lagostas inteiras cozidas congeladas e caudas de lagosta congelada para exportação. A aplicação de um checklist de controle higiênico-sanitário nas indústrias visitadas resultou em uma classificação global de conformidades maior que 96% dos aspectos analisados. O desenvolvimento do plano APPCC resultou na detecção de dois pontos críticos de controle (PCC), incluindo o recebimento e etapas de classificação, no processamento de lagosta congelada e caudas de lagosta congelada, e um PCC adicional foi detectado no processamento de lagosta inteira cozida congelada na etapa de cozimento. A correta implantação do plano APPCC nas indústrias de processamento de lagosta estudadas demonstrou ser o método mais seguro e efetivo economicamente para o controle dos perigos em cada PCC.

This study aimed to verify the hygienic-sanitary working practices and to create and implement a Hazard Analysis Critical Control Point (HACCP) in two lobster processing industries in Pernambuco State, Brazil. The industries studied process frozen whole lobsters, frozen whole cooked lobsters, and frozen lobster tails for exportation. The application of the hygienic-sanitary checklist in the industries analyzed achieved conformity rates over 96% to the aspects evaluated. The use of the Hazard Analysis Critical Control Point (HACCP) plan resulted in the detection of two critical control points (CCPs) including the receiving and classification steps in the processing of frozen lobster and frozen lobster tails, and an additional critical control point (CCP) was detected during the cooking step of processing of the whole frozen cooked lobster. The proper implementation of the Hazard Analysis Critical Control Point (HACCP) plan in the lobster processing industries studied proved to be the safest and most cost-effective method to monitor each critical control point (CCP) hazards.

Este estudo teve como objetivo avaliar o efeito de diferentes meios de crescimento [caldo BHI, caldo BHI adicionado de glucose (10 g/100 mL) e caldo BHI adicionado de NaCl (5 g/100 mL)] e temperaturas de incubação (28 e 37 ºC) sobre a adesão, separação e formação de biofilme sobre superfícies (2 x 2 cm) de polipropileno e aço inoxidável durante longo tempo de incubação (24-72 h) por parte de cepas de Staphylococcus aureus (S3, S58 e S54) isoladas de plantas de processamento de alimentos. Também foi avaliada a eficácia dos sanitizantes hipoclorito de sódio (250 mg/mL) e ácido peracético (30 mg/mL) na redução do número de células bacterianas viáveis presentes em um biofilme pré-formado. As cepas de S. aureus aderiram em número mais elevado quando incubadas em caldo BHI em ambos os tipos de superfícies e temperaturas de incubação testadas. A separação das células das superfícies revelou alta persistência ao longo do período de incubação. Número de células necessário para a formação do biofilme foi detectado depois de três dias de incubação em todos os sistemas experimentais. O ácido peracético e o hipoclorito de sódio não foram eficientes em remover completamente a células de S. aureus aderidas sobre as superfícies de polipropileno e aço inoxidável. Os resultados obtidos revelaram alta capacidade das cepas ensaiadas em aderir e formar biofilme sobre superfícies de polipropileno e aço inoxidável sobre diferentes condições de crescimento e que as células na matriz do biofilme apresentaram-se resistentes à total remoção quando expostas aos sanitizantes hipoclorito de sódio e ácido peracético.

This study assessed the effect of different growth media [BHI broth, BHI broth plus glucose (10 g/100 mL) and BHI broth plus NaCl (5 g/100 mL)] and incubation temperatures (28 or 37 ºC) on the adherence, detachment and biofilm formation on polypropylene and stainless steel surfaces (2 x 2 cm coupons) for a prolonged period (24-72 h) by some strains of Staphylococcus aureus (S3, S28 and S54) from food processing plants. The efficacy of the sanitizers sodium hypochlorite (250 mg/mL) and peracetic acid (30 mg/mL) in reducing the number of viable bacterial cells in a preformed biofilm was also evaluated. S. aureus strains adhered in highest numbers in BHI broth, regardless of the type of surface or incubation temperature. Cell detachment from surfaces revealed high persistence over the incubation period. The number of cells needed for biofilm formation was noted in all experimental systems after 3 days. Peracetic acid and sodium hypochlorite were not efficient in completely removing the cells of S. aureus adhered onto polypropylene and stainless steel surfaces. From these results, the assayed strains revealed high capacities to adhere and form biofilms on polypropylene and stainless steel surfaces under the different growth conditions, and the cells in biofilm matrixes were resistant to total removal when exposed to the sanitizers sodium hypochlorite and peracetic acid.

Over the past few years, the use of probiotics, which are capable of exerting beneficial effects on the composition of intestinal microbiota, has increased. Cheeses have been suggested as a better carrier of probiotic bacteria than other fermented milk products. The effect of added cultures of probiotic lactic acid bacteria on the quality of a Brazilian goat semi-hard cheese (coalho) was assessed during 21 days of storage at 10 ºC as follows: C1, Lactococcus lactis subsp. lactis and L. lactis subsp. Cremoris (standard cheese); C2, Lactobacillus acidophilus (LA-5); C3, Lactobacillus paracasei (Lactobacillus casei-01); C4, BBifidobacterium lactis (BB12); and C5, L. acidophilus, L. paracasei and B. lactis. Differences in some physico-chemical, experimental texture and proteolysis parameters were found among the assessed cheeses. All of them presented high luminosity (L*) with predominance of the yellow component (b*). Numbers of lactic acid bacteria in the cheeses were greater than 10(7) cfu g-1 during storage. Cheeses with the added probiotic strains alone and in co-culture were better accepted than cheeses without the probiotic strains. It is suggested that goat "coalho" cheese could be a potential carrier of probiotic lactic acid bacteria.

Este estudo teve como objetivo avaliar o potencial de utilização da carne de ovinos de descarte na elaboração de mortadelas. Três formulações de mortadela foram desenvolvidas, com 90, 80 e 70% de carne ovina, adicionadas de 10, 20 e 30% de gordura suína. Os resultados demonstraram que as três formulações de mortadela atenderam aos parâmetros microbiológicos preconizados pela legislação brasileira, sendo, portanto, seguros para o consumo humano. Para os parâmetros cinzas, amido, cloretos, pH e atividade de água não houve diferença estatística entre as formulações (P>0,05). Os valores obtidos na análise de umidade diferiram estatisticamente entre os tratamentos (P<0,05), aumentando os valores médios, à medida que foram aumentados os percentuais de carne adicionados, ficando a formulação com 90% de carne fora dos padrões recomendados pela legislação brasileira. A mortadela elaborada com 90% de carne obteve maiores percentuais nas análises de estabilidade de emulsão e capacidade de retenção de água. A formulação elaborada com 90% de carne se diferenciou das demais estatisticamente na análise sensorial, sendo a ela atribuídos escores menores para os atributos de textura e avaliação global. Na avaliação da intenção de compra, os avaliadores comentaram que comprariam os produtos independente das formulações. Os resultados demonstram que a carne de ovinos de descarte é uma opção viável na elaboração de mortadela, uma vez que resulta em produtos com elevado grau de aceitação e qualidade nutricional, agregando valor aos cortes de ovinos.

The aim of this study was to evaluate the potential use of spent lamb meat in the preparation of mortadella. Three formulations of mortadella were developed, using 90, 80 and 70% of lamb meat, each with 10, 20 and 30% of pork fat, respectively. The results showed that the proposed formulations met the microbiological parameters recommended by the Brazilian legislation, being, therefore, a safe meat product for human consumption. The parameters of ashes, starch, sodium chloride, pH and water activity showed no significant difference among the formulations (P>0.05). The moisture contents differed significantly from one sample to the other (P<0.05). An increase in the amount of lamb meat in the mortadella formulation resulted in an increase in moisture; this made the formulation with 90% meat improper, according to the standards recommended by the Brazilian legislation. The mortadella with 90 % meat had the highest percentages of emulsion stability and water holding capacity. The sensory evaluation showed that the formulation with 90% lamb meat presented the lowest scores of texture and overall acceptance. However, the evaluators commented that they would buy any of the products regardless of the formulation. The results show that the use of spent lamb meat is a viable option for the preparation of mortadella, as the resulting products have been widely accepted. In addition, it also gives spent lamb carcasses more commercial value.

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.

Este estudo teve como objetivo realizar a caracterização físico-química, microbiológica e sensorial do queijo de leite de cabra tipo Coalho condimentado com cumaru (Amburana cearensis A.C. Smith), produzido na Região do Cariri do Estado da Paraíba, Brasil. Os valores médios obtidos para umidade, proteínas, lipídeos, gordura em extrato seco, cinzas e acidez em ácido lático foram de 46,5; 23,9; 25,3; 47,5; 3,8; 0,09%, respectivamente. Todas as amostras apresentaram contagem de coliformes totais > 2,4 × 10³ NMP.g-1 e coliformes fecais oscilando entre 0,3 × 10¹ e > 2,0 × 10³ NMP.g-1. Não foi detectada presença de Salmonella. Para as contagens de mesófilos, fungos e Staphylococcus coagulase positiva, foram encontrados valores entre 3,7 × 10(4) e 5,6 × 10(8); 4,6 × 10² e 5,2 × 10(9); < 10¹ e 8,0 × 10(5) UFC.g-1, respectivamente. Os testes sensoriais revelaram boa aceitação geral, bem como satisfatório resultado na intenção de compra do produto. A boa aceitação do queijo mostra seu potencial de ampliação de consumo. Entretanto, os resultados das análises microbiológicas ressaltam a necessidade de melhor monitoramento das etapas envolvidas no seu processamento, com o intuito de obter um produto de melhor qualidade microbiológica.

This study aimed to carry out the physicochemical, microbiological and sensory characterization of coalho-like goat's milk cheese with added coumarou (Amburana cearensis A.C. Smith), manufactured in the Cariri region, Paraíba State, Brazil. The average values obtained for moisture, protein, fat, fat in the dry extract, ash and acidity as lactic acid were 46.5; 23.9; 25.3; 47.5; 3.8 and 0.09%, respectively. All the samples analyzed presented total coliform counts > 2.4 x 10³ MPN.g-1, while the faecal coliforms ranged between 0.3 x 10¹ - > 2.0 x 10³ MPN.g-1. Salmonella was not found in any of the samples. The mesophilic, fungal and coagulase-positive Staphylococcal counts were between 3.7 x 10(4)-5.6 x 10(8); 4.6 x 10²-5.2 x 10(9); and > 10¹-8.0 x 10(5) CFU.g-1, respectively. The sensory tests showed good acceptance of the product assessed and satisfactory results for purchasing intent. The good acceptance of the cheeses evaluated showed the potential for increased consumption. However, the results of the microbiological analyses showed the need for better monitoring of the steps involved in its processing, in order to obtain a product with better microbiological quality.

A algaroba [Prosopis juliflora (SW) D.C.] é uma planta tropical perene comumente encontrada no semi-árido brasileiro e apresenta-se como matéria-prima viável para o processo fermentativo por possuir baixo custo e para produzir vagens que contém um elevado teor de açúcares hidrolisáveis, os quais podem gerar diversos compostos, incluindo etanol. Avaliou-se o uso de vagens de algaroba como substrato para produção de etanol por Z. mobilis UFPEDA-205 por meio de fermentação submersa. O processo fermentativo foi avaliado por meio da mensuração da taxa de conversão de substrato em etanol, taxa de produção de etanol e eficiência de fermentação. Os valores muito próximos encontrados para o fornecimento máximo teórico (170 g L-1) e experimental (165 g L-1) de etanol foram alcançados após 36 h de fermentação. O valor de contagem experimental de Z. mobilis UFEPEDA-205 (próximo a 6 Log cfu mL-1) foi encontrado após 36 h de fermentação. As mais elevadas taxas de conversão de substrato para etanol (0,44 g ethanol g glucose-1), de produção de etanol (4,69 g L-1 h-1) e de eficiência de fermentação (86,81%) foram encontrados depois de 30 h. Conclui-se que as vagens de algaroba apresentam potencial como substrato emergente para produção de etanol por Z. mobilis por meio de fermentação submersa.

Mesquite [Prosopis juliflora (SW) D.C.], a perennial tropical plant commonly found in Brazilian semi-arid region, is a viable raw material for fermentative processes because of its low cost and production of pods with high content of hydrolysable sugars which generate many compounds, including ethanol. This study aimed to evaluate the use of mesquite pods as substrate for ethanol production by Z. mobilis UFPEDA205 in a submerged fermentation. The fermentation was assessed for rate of substrate yield to ethanol, rate of ethanol production and efficiency of fermentation. The very close theoretical (170 g L-1) and experimental (165 g L-1) maximum ethanol yields were achieved at 36 h of fermentation. The highest counts of Z. mobilis UFEPEDA-205 (both close to 6 Log cfu mL-1) were also noted at 36 h. Highest rates of substrate yield to ethanol (0.44 g ethanol g glucose-1), of ethanol production (4.69 g L-1 h-1) and of efficiency of fermentation (86.81%) were found after 30 h. These findings suggest mesquite pods as an interesting substrate for ethanol production using submerged fermentation by Z. mobilis.

O queijo de coalho é amplamente produzido e consumido na região Nordeste do Brasil, sendo principalmente fabricado por pequenos produtores rurais. Este produto tem sido caracterizado por uma alta carga microbiana, significando um risco para a saúde dos consumidores. Este estudo teve como objetivo identificar os compostos químicos do óleo essencial extraído das folhas de Eugenia caryophyllata; avaliar o efeito inibitório do óleo essencial sobre microrganismos contaminantes de queijo de coalho; e verificar sua eficácia em inibir a microflora autóctone do produto durante o armazenamento refrigerado. Eugenol (74%) apresentou-se como o composto mais prevalente no óleo essencial. Os valores de Concentração Inibitória Mínima (CIM) e Concentração Microbicida Mínima (CMM) em meio sintético variaram entre 2,5-5 e 5-20 µg.mL-1, respectivamente. As amostras de queijo de coalho embaladas a vácuo e adicionadas de 5, 10 e 20 µg.g-1 de óleo essencial apresentaram uma menor taxa de crescimento (efeito microstático) de bactérias mesófilas ao longo dos intervalos avaliados. De outra forma, o óleo essencial em concentrações variando entre 2,5 e 10 µg.g-1 causou considerável redução da contagem de fungos nas amostras de queijo ao longo do armazenamento. Estes resultados revelam a destacável propriedade antimicrobiana do óleo essencial extraído das folhas de E. caryophyllata frente a uma variedade de microrganismos contaminantes de queijo de coalho em meio laboratorial e na matriz alimentar.

Coalho cheese (a firm but very lightweight cheese produced in Brazil) is widely produced and consumed in the Brazilian Northeast and its production has been mainly related to small farmers. This food has been frequently characterized as having high microbial load posing a risk for the health of consumers. This study aimed to indentify the chemical compounds of the essential oil from Eugenia caryophyllata leaves; to evaluate the inhibitory effect of the oil against coalho cheese contaminating microorganisms; and to assess its efficacy in inhibiting the autochthonous microflora of the cheese during refrigerated storage. Eugenol (74%) was found to be the most prevalent compound in the essential oil. Minimum Inhibitory Concentration (MIC) and Minimum Cidal Concentration (MCC) in laboratorial broth were in the range of 2.5-5 and 5-20 µg.mL-1, respectively. Vaccum packed coalho cheese added with 5, 10, and 20 µg.g-1 of oil showed a lower growth rate (like-static effect) against mesophilic bacteria during the time intervals evaluated. On the other hand, 2.5-10 µg.g-1 of oil provided a prominent decrease toward fungi count in cheese samples during storage. These results reveal the interesting antimicrobial property of the essential oil from E. caryophyllata leaves against a range of coalho cheese-related microorganisms in laboratorial media and in food matrix.

Cinnamomum zeylanicum Blume, Lauraceae, é uma espécie vegetal reconhecida, a longo tempo, como possuidora de muitas propriedades biológicas. Este estudo objetivou identificar os constituintes do óleo essencial das folhas de C. zeylanicum, utilizando CG-EM, e avaliar seu efeito inibitório sobre Salmonella enterica, Escherichia coli, Staphylococcus aureus e Pseudomonas aeruginosa através da determinação da CIM e CBM, bem como através da análise do tempo de morte bacteriana. Eugenol (73,27%) foi o composto mais prevalente no óleo essencial, seguido por trans-β-cariofileno (5,38%), linalol (3,31%) e álcool acetato cinâmico (2,53%). Os resultados mostraram uma interessante atividade antibacteriana do óleo essencial com CIM, variando de 1,25 a 10 µL.mL-1. Os valores de CBM oscilaram entre 20 e 80 µL.mL-1. O óleo essencial na concentração de 10 e 40 µL.mL-1 causou uma rápida e constante diminuição (2 a 5 ciclos logarítmicos) na contagem de células viáveis de todas as cepas ensaiadas ao longo de 24 horas. O óleo essencial na concentração de 40 µL.mL-1 causou uma total eliminação do inóculo inicial de S. aureus depois de 2 horas. Estes resultados mostram a possibilidade do uso do óleo essencial extraído das folhas de C. zeylanicum como uma fonte alternativa de compostos antimicrobianos para aplicação em sistemas de conservação de alimentos.

Cinnamomum zeylanicum Blume, Lauraceae, has long been known for having many biological properties. This study aimed to identify the constituents of the essential oil from C. zeylanicum leaves using GC-MS and to assess its inhibitory effect on Salmonella enterica, Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa based on MIC and MBC determination and kill-time study. Eugenol (73.27%) was the most prevalent compound in the essential oil followed by trans-β-cariophyllene (5.38%), linalool (3.31%), and alcohol cinamic acetate (2.53%). The results showed an interesting antibacterial activity of the oil with MIC ranging from 1.25 to 10 µL.mL-1. MBC values were in the range of 20 - 80 µL.mL-1. A concentration of 10 and 40 µL.mL-1 of the essential oil caused a fast and steady decrease in viable cell count (2 to 5 log cycles) of all assayed strains along 24 hours. A concentration of 40 µL.mL-1 of the oil provided a total elimination of the initial inocula of S. aureus after 2 hours. These results show the possibility of regarding the essential oil from C. zeylanicum leaves as alternative sources of antimicrobial compounds to be applied in food conservation systems.

O óleo essencial de Origanum vulgare L. tem sido reconhecido como uma interessante fonte de compostos antimicrobianos para ser aplicado na conservação de alimentos. Neste estudo, avaliou-se o efeito do óleo essencial de O. vulgare sobre o crescimento de A. flavus, A. parasiticus, A. fumigatus, A. terreus e A. ochraceus. O óleo essencial apresentou um significante efeito inibitório sobre todos os fungos ensaiados. A CIM foi 0,6 µL.mL-1 para todos os fungos, enquanto a CFM variou entre 1,25-2,5 µL.mL-1. O crescimento micelial radial de A. flavus e A. parasiticus foi fortemente inibido ao longo de 14 dias pelo óleo essencial nas concentrações de 0,6; 1,25; e 2,5 µL.mL-1 em meio sólido. O óleo essencial a 0,6 e 0,3 µL.mL-1 inibiu o aumento da massa micelial de todos os fungos em valores superiores a 90% em meio líquido, enquanto a 1,25 µL.mL-1, a inibição foi de 100%. O óleo essencial em variadas concentrações (0,6-2,5 µL.mL-1) inibiu a viabilidade e germinação dos esporos fúngicos em um curto tempo de exposição. As principais alterações morfológicas provocadas pelo óleo essencial em A. parasiticus, observadas sob microscopia óptica, foram ausência de conidiação, perda de citoplasma, perda de pigmentação e ruptura de estrutura celular. Estes resultados demonstraram que o óleo essencial de O. vulgare exerce um significante efeito fungitóxico, suportando seu uso racional como agente antifúngico na conservação de alimentos.

Origanum vulgare L. essential oil has been known as an interesting source of antimicrobial compounds to be applied in food conservation. In this study, the effect of O. vulgare essential on the growth of A. flavus, A. parasiticus, A. fumigatus, A. terreus and A. ochraceus was assessed. The essential oil had a significant inhibitory effect on all assayed fungi. MIC was 0.6 µL.mL-1 for all fungi, while MFC was in the range of 1.25-2.5 µL.mL-1. The radial mycelial growth of A. flavus and A. parasiticus was strongly inhibited over 14 days at 0.6, 1.25 and 2.5 µL.mL-1 of oil in solid medium. The mycelial mass of all fungi was inhibited over 90% at 0.6 and 0.3 µL.mL-1 in liquid medium, while it was 100% at 1.25 µL.mL-1. The oil in a range of concentrations (0.6 to 2.5 µL.mL-1) was effective in inhibiting the viability and spores germination in a short time of exposure. The main morphological changes caused by the essential oil in A. parasiticus observed under light microscopy were absence of conidiation, leakage of cytoplasm, loss of pigmentation, and disrupted cell structure. These results demonstrated that O. vulgare essential oil produced a significant fungitoxic effect supporting its possible rational use as anti-mould compound in food conservation.

O objetivo deste estudo foi observar a eficácia do óleo essencial de O. vulgare L. e O. majorana L. na inibição do crescimento e sobrevivência de cepas de fungos potencialmente patogênicas, bem como avaliar os possíveis mecanismos envolvidos no estabelecimento da propriedade antifúngica dos óleos essenciais testados através do ensaio de estabilidade osmótica e morfogênese. As cepas fúngicas utilizadas neste estudo foram Candida albicans ATCC 7645, C. tropicalis LM-14, C. krusei LM-09, Cryptococcus neoformans FGF-5, Aspergillus flavus LM-02, A. fumigatus IPP-21, T. rubrum ATCC 28184, T. mentagrophytes LM-64, Microsporum gypseum ATCC 184, M. canis LM-36 e Cladosporium herbarium ATCC 26362. O óleo essencial de O. vulgare apresentou valor de CIM de 80 µL/mL, enquanto o óleo essencial de O. majorana apresentou valor de CIM de 160 µL/mL. C. krusei LM-09 apresentou-se como a única cepa resistente a todas as concentrações ensaiadas de ambos os óleos essenciais. Os óleos essenciais testados quando ensaiadas em seu valor de CIM causaram um efeito fungicida contra C. albicans ATCC 7645 após 4 h de exposição. O óleo essencial de O. vulgare na concentração de 80 µL/mL exibiu uma total inibição do crescimento micelial radial de T. rubrum ATCC 28184 e M. canis LM-36 ao longo de 14 dias. As cepas fúngicas ensaiadas quando tratadas com sorbitol (agente osmo-protetor) foram capazes de crescer em meio adicionado de mais altas concentrações dos óleos essenciais quando comparados ao meio não adicionado de sorbitol, sugerindo especificidade destes produtos a parede celular como alvo na célula fúngica. As principais alterações causadas pelo óleo essencial de O. vulgare sobre a morfologia de A. flavus LM-02 foram diminuída conidiação, perda de citoplasma, perda de pigmentação e ruptura da estrutura celular indicando degeneração da parede celular fúngica. Estes resultados sugerem que óleos essenciais de espécies de Origanum poderiam ser considerados como potenciais antifúngicos para o controle de fungos patógenos e ocorrência de micoses.

This study aimed to assess the efficacy of O. vulgare L. and O. majorana L. essential oil in inhibiting the growth and survival of potentially pathogenic fungal strains and also sought to evaluate the possible mechanisms involved in the establishment of the antifungal property of the tested essential oils through assays of osmotic stability and morphogenesis. Test strains included in this study were Candida albicans ATCC 7645, C. tropicalis LM-14, C. krusei LM-09, Cryptococcus neoformans FGF-5, Aspergillus flavus LM-02, A. fumigatus IPP-21, T. rubrum ATCC 28184, T. mentagrophytes LM-64, Microsporum gypseum ATCC 184, M. canis LM-36 and Cladosporium herbarium ATCC 26362. O. vulgare essential oil presented a MIC value of 80 µL/mL, while for O. majorana this was 160 µL/mL. C. krusei LM-09 was the only strain resistant to all assayed concentrations of both essential oils. O. vulgare and O. majorana essential oil at their MIC values provided a cidal effect against C. albicans ATCC 7645 after 4 h of exposure. O. vulgare essential oil at 80 µL/mL exhibited 100 % inhibition of the radial mycelia growth of T. rubrum ATCC 28184 and M. canis LM-36 for 14 days. Assayed fungus strain protected by sorbitol (osmo-protectant agent) grew in media containing higher concentrations of O. vulgare and O. majorana essential oil in comparison to media without sorbitol, suggesting some specificity of these essential oils for targeting cell wall in the fungi cell. Main morphological changes observed under light microscopy provided by the essential oil of O. vulgare in A. flavus LM-02 were decreased conidiation, leakage of cytoplasm, loss of pigmentation and disrupted cell structure indicating fungal wall degeneration. These results suggest that essential oils from Origanum could be regarded as a potential antifungal compound for controlling the growth of pathogen fungi and the occurrence of mycoses.