Atividade antimicrobiana de óleos essenciais e associações com conservantes de alimentos

Abstract

Increasing food production brings out the need for new technologies that improve food preservation with less risk to human health. Thus, this study evaluated the activity of essential oils against pathogenic foodborne microorganisms, and the synergistic effect of these withfood preservatives. Four microorganisms were used: Gram-positive bacteria: Bacillus cereusand Staphylococcus aureus and Gram-negative bacteria: Salmonella typhi and Escherichia coli. Essential oils of cinnamon, ginger, peppermint, tea tree and tangerine were used in addition to chemical preservatives methylparaben and acetic acid. Tests of associations with essential oils and preservatives were performed, determining the minimum inhibitory concentration and verifying the presence or absence of synergism. Tangerine essential oil showed no bactericidal potential and non-efficacy for microbial growth control. The tea tree essential oil presented satisfactory results when isolated (1.04 mg.mL-1for E. coli) but showed negative effects when tested in combination with chemical preservatives. The best results were related to cinnamon essential oil, with the lowest inhibitory concentrations (0.351 mg.mL-1 for Salmonella typhi) and presence of synergism when combined with chemicalpreservative methylparaben, significantly reducing the effective concentration of the preservative (0.470 to 0.059 mg.mL-1for Salmonella typhi). It can be conclude that the association between the essential oil of cinnamon and methylparaben consist in an excellent alternative for food preservation.