Antifungal Activity of the Onion (Allium cepa L.) Essential Oil Against Aspergillus, Fusarium and Penicillium Species Isolated from Food

The aim of this study was to investigate the antifungal potential of onion (Allium cepa L. cultivar Kupusinski jabučar) essential oil against fungal species isolated from food. Twenty one compounds were identified in the onion essential oil and the major components were dimethyl‐trisulfide (16.64%) and methyl‐propyl‐trisulfide (14.21%). Applied concentrations of onion essential oil (3.5, 7.0, 14.0, and 28.0 μL/100 mL) caused the delay or absence of fungal growth with different inhibitory effects on the deceleration in the growth rate. Onion essential oil at a concentration of 28.0 μL/100 mL demonstrated a fungicidal effect on the growth of Aspergillus carbonarius, Aspergillus wentii, Aspergillus versicolor, Penicillium brevicompactum, Penicillium glabrum, Penicillium chrysogenum, and Fusarium spp. and an inhibitory effect on Aspergillus niger and Penicillium aurantiogriseum. Macroscopic and microscopic investigations showed that the application of onion essential oil caused changes in macro‐morphology and micro‐morphology of the investigated fungi. Practical Applications The obtained results show that onion essential oil, in addition to the basic sensory role in a food product, can also be used as antifungal agent in food protection from mycological and mycotoxicological contamination.