Antifungal activity of essential oil from Lippia alba cultivated in Senegal against mycotoxigenic fungal species associated with stored food commodities

The contamination of stored cereals and oilseeds by mycotoxigenic fungi represents a major challenge for food safety and public health in Senegal. In this context, there is a growing interest in developing natural alternatives to synthetic fungicides for post-harvest protection. This study aims to evaluate the antifungal activity of Lippia alba (Mill.) essential oil against four fungal species associated with stored commodities and known producers of major mycotoxin families.
The essential oil was extracted from a mixture of leaves, flowers, and fruits of plants cultivated in Senegal, and analyzed by gas chromatography-mass spectrometry (GC-MS). Its chemical composition revealed a chemotype dominated by limonene (44.32%) and citral (27.91%).
Antifungal activity was assessed using direct contact assays based on the incorporation of the essential oil into Potato Dextrose Agar (PDA) medium. Four fungal species were investigated: Aspergillus flavus, Aspergillus niger, Fusarium oxysporum, and Fusarium verticillioides. Tested concentrations ranged from 0.25 to 2 mg/mL. Mycelial growth was monitored over 7 days, and the antifungal effect was assessed based on mycelial growth inhibition, determined by colony diameter measurements and percentage inhibition.
Antifungal assays showed dose-dependent inhibition of fungal growth. Fusarium species were found to be more sensitive to L. alba essential oil than Aspergillus species. At a concentration of 2 mg/mL, mycelial growth inhibition exceeded 50% for both F. oxysporum and F. verticillioides, highlighting a promising antifungal potential. Overall, these findings underscore the potential of L. alba essential oil and support its valorization as a natural biopesticide for the protection of stored food products in Senegal. Further studies to evaluate the antifungal activity in the volatile phase are currently underway.