Atividade antimicrobiana do óleo essencial do capim limão (Cymbopogon citratus) e sua interação com os componentes dos alimentos

Abstract

In the present study was determined the antimicrobial activity of the essential oil (EO) of Cymbopogon citratus - (DC) Stapf and the eff ect of food components on its eff ectiveness. The antimicrobial activity of the oil was determined by the presence of the growth inhibition zone and minimum inhibitory concentration against Listeria monocytogenes, L. innocua, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Salmonella choleraesuis. The eff ect of food components and pH on the antimicrobial efficacy of oil was monitored by the growth of L. monocytogenes in model medias, constituted of potato starch (0, 1, 5 and 10%), meat extract (1.5, 3, 6 and 12%), sunflower oil (0, 5 and 10%) and tripticase soy broth (TSB) at pH 4, 5, 6 and 7. The EO was eff ective against all bacterial species tested. The antimicrobial eff ect of the oil vary depending on the concentration of the component manipulated. Proteins and lipids showed negative impact on the eff ectiveness of the EO, the higher the concentration of these components in the media were major bacterial growth medium. The starch had a negative impact on the eff ectiveness of the oil in concentrations of 1% and 5%. However, the highest concentration evaluated (10%) showed a decline in bacterial growth. The antimicrobial activity of EO increased with decreasing pH. The results of this study demonstrate the efficacy of antimicrobial OE C. citratus against pathogens and spoilage bacteria and that has a higher efficiency in protein and starchy foods at acidic pH.