Antifungal Activity and Potential Use of Essential Oils Against Fusarium culmorum and Fusarium verticillioides

Essential oils of bay leaf, cinnamon, clove and oregano were tested in vitro and oregano essential oil in vivo, against two foodborne fungi belonging to the dominant mycobiota of stored rice, Fusarium culmorum and Fusarium verticillioides, collected from the Albuferarice-producing Mediterranean area near Valencia (Spain). Chemical composition was identified by gas chromatography-mass spectrometry. Essential oils presented a high percentage of oxygenated components: 78.8 % in bay leaf (eucalyptol 51 %); 90.3 % in clove (eugenol 89.8 %); 92 % in cinnamon (eugenol 60 % and eugenyl acetate18.3 %); 71.8 % in oregano (carvacrol 49.6 % and thymol 21.2 %). Monoterpenes and sesquiterpenes were: 18 % in bay leaf, 9 % in clove, 5 % in cinnamon, 25 % in oregano. This research showed that essential oils have a great potential to control both fungal pathogens. In the in vitro test, the essential oils of cinnamon, clove and oregano reduced fungal growth by 90 % and almost 100 %, being oregano the most effective essential oil to inhibit fungal growth. The effect of the oregano essential oil on fungal development in inoculated rice grains demonstrated its effectiveness.