Vol. 7, Issue 10, Part I (2025)

Maize is a staple food crop in Kenya which is often affected by the growth of fungi. These fungi produce mycotoxins which are hazardous to both human and animal health. The common mycotoxins present in maize and maize products are aflatoxins, Fumonisins, ochratoxins and penicillins. To address this concern, several methods have been put in place to counter the growth of fungi, however, no single method have been found effective. There has been an increased interest on plant based antifungal agents over synthetic fungicides due to environmental and health impacts. This study assessed antifungal activity of Warburgia ugandensis water and methanol extracts against Aspergillus flavus and Fusarium verticillioides, phytochemical composition and application in maize grain preservation. The antifungal activity of Warburgia ugandensis extracts were assessed using disc diffusion assay and the minimum inhibitory concentration (MIC) of the extracts also determined. Effectiveness of these extracts in preserving maize grains was also evaluated by treating the inoculating maize grains with the extracts. Chemical composition of the extracts was also determined using gas chromatography-mass spectrometry (GC-MS). Warburgia ugandensis extracts exhibited potent antifungal activity against both F. verticillioides and A. flavus. Methanol extract had higher antifungal against F. verticillioides (ZOI=30mm) while water extracts had a higher antifungal activity against A. flavus (ZOI=18mm). The MIC values of both extracts were 125mg/ml. Treatment with plant extracts effectively preserved maize grains from fungal contamination, with methanol extract being more effective. The GC-MS revealed the presence of a variety of chemical compounds in the extracts. Gas Chromatography-Mass Spectrometry analysis revealed 9-t-Butyl-4-iodo-2,2-dimethyladamantane (45.01%) and Cycloisolongifolene, 8,9-dehydro-9-formyl-(7.60%), while Ledene oxide-(II) (31.19%) as the most dominant compounds in water extracts. Notably, 9-t-Butyl-4-iodo-2,2-dimethyladamantane dominated the water extract, while while Ledene oxide-(II) (31.19%), Pregn-4-ene-1,20-dione, 12-hydroxy-16,17-d (21.51%) were dominating compounds in methanol extract. The most dominant compounds have been reported to possess antifungal activities hence underscoring the potential of Warburgia ugandensis extracts as natural antifungal bio preservatives therefore contributing to food safety and security.