Inhibition of growth and aflatoxin production in Aspergillus parasiticus by essential oils of selected plant materials.

We studied the effect of 13 chemically different essential oils (EO) on the mycelial growth of and aflatoxin synthesis by Aspergillus parasiticus. Cinnamon, thyme, oregano, and cumin EO were able to stop mycelial growth at only 0.1% in the medium, while curcumin, ginger, lemon, and orange EO were unable to inhibit totally the growth even at 1% concentration. Coriander, black pepper, mugwort, bay, and rosemary EO caused the growth to stop at concentrations between 0.2 and 1%. The EO most active upon mycelial growth were also the most active against aflatoxinogenesis. However, aflatoxin synthesis was inhibited by all the EO at higher extent than the mycelial growth.