Propriedade antibacteriana de óleos essenciais de especiarias sobre bactérias contaminantes de alimentos Antibacterial property of spice essential oils on food contaminating bacteria

As especiarias são conhecidas por exercerem uma estabilidade frente à ação de microrganismos, estando inseridas no grupo dos alimentos estáveis. Esta propriedade conservante das especiarias está relacionada com a presença de compostos antibacterianos na sua composição. Tais compostos podem ser usados no combate a bactérias deteriorantes de alimentos, por esse motivo, este trabalho visa à investigação da propriedade antimicrobiana dos óleos essenciais de Cinnamomum zeylanicum Blume, Coriandrum sativum L., Cuminum cyminum L., Mentha. piperita L., Ocimum basilicum L., Origanum majorana L., Pimpinella anisum L., Piper nigrum L., Rosmarinus officinalis L. e Zingiber officinalis Rosc. frente a bactérias contaminantes de alimentos. Para esse estudo, foram selecionadas 10 cepas bacterianas deteriorantes de alimentos. Para a realização dos ensaios antibacterianos, foi utilizado o método de difusão em meio sólido. Os resultados mostram que os óleos essenciais das folhas do E. caryophyllata e da C. zeylanicum mostraram uma eficiência na inibição de todas as cepas bacterianas ensaiadas. Os outros óleos produziram atividade antibacteriana, porém com menor espectro de ação. A pesquisa de tais produtos mostra-se bastante promissora, sendo essa uma boa alternativa para a substituição de aditivos químicos em alimentos.<br>Spices are known for their stability against microbial action; that being so, they are included in the group of stable foods. This preservative property of spices is related to the presence of antibacterial compounds in their composition. Such compounds could be used to control the food contaminating bacteria. This study aimed to assess the antimicrobial property of the essential oils from Cinnamomum zeylanicum Blume, Coriandrum sativum L., Cuminum cyminum L., Mentha. piperita L., Ocimum basilicum L., Origanum majorana L., Pimpinella anisum L., Piper nigrum L., Rosmarinus officinalis L., and Zingiber officinalis Rosc. against food related bacteria. Therefore, 10 species of degenerating food bacteria were selected. The solid medium diffusion procedure was used to carry out the antimicrobial assays. The results showed that essential oils from E. caryophyllata and C. zeylanicum are efficient in inhibiting all assayed bacterial strains. The other assayed oils presented some antibacterial activity but with smaller action spectrum. The research of the antimicrobial activity of the essential oils is quite promising, and it is a possible alternative for replacing food additives

Inhibitory effect of the essential oil from Eugenia caryophyllata Thumb leaves on coalho cheese contaminating microorganisms

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

Anti-staphylococcal effectiveness of nisaplin in refrigerated pizza doughs

This study evaluated the effectiveness of nisaplin, commercial product having nisin as active component, in decreasing the staphylococcal population in refrigerated pizza doughs. The refrigerated pizza dough pieces randomly chosen were dipped in the solutions with nisaplin concentrations of 1.0 x 10-3 g and 1.0 x 10-2 g nisaplin/mL named for the treatment A and B and kept under refrigeration (7 °C ± 1 °C). On times 0, 15 and 30 days post treatment the Staphylococcus spp. count was carried out. The results showed that both nisaplin treatments were able to reduce the Staphylococcus spp. count (CFU/g) in the refrigerated pizza doughs. However, only treatment B showed statistically significant reducer effect (p < 0.05) on the count providing a decrease of 1.0 and 0.98 log cycles, respectively, after 15 and 30 days post treatment. These data suggest that nisin could appear as promising alternative to control the survival of the pathogen microorganisms in the foods, particularly, Staphylococcus in the refrigerated pizza doughs.<br>Este estudo avaliou a efetividade de nisaplin, produto comercial tendo nisina como componente ativo, em diminuir a população estafilocócica em massas de pizza refrigeradas. Pedaços de massa de pizza refrigerada foram randomicamente escolhidos e mergulhados em soluções de nisaplin com concentração de 1.0 10-3 g e 1.0 10-2 g nisaplin/mL, nomeados, respectivamente, tratamento A e B, e mantidos sob refrigeração (7 °C ± 1°C). Nos tempos 0, 15 e 30 dias pós-tratamento foram feitas as contagens de Staphylococcus spp. Os resultados mostraram que ambos os tratamentos diminuíram a contagem (UFC/g) de Staphylococcus spp. em massas de pizza refrigeradas. Entretanto, somente o tratamento B mostrou um efeito redutor estatisticamente significante (p < 0.05) sobre a contagem de Staphylococcus spp. causando uma diminuição de 1.0 e 0.98 ciclos logarítmicos, respectivamente, nos tempos 15 e 30 dias pós tratamento. Estes dados sugerem que nisina poderia apresentar-se como uma promissora alternativa para controlar o a sobrevivência de microrganismos patógenos em alimentos, particularmente, espécies de Staphylococcus em massas de pizza refrigerada