Synergistic inhibition of mycotoxigenic fungi contaminating bell pepper fruits by combination of citronella and lemongrass essential oils

Bell pepper fruits (Capsicum annum L.) fungal infection can result in the contamination of these fruits by mycotoxins. The aim of the current study was to evaluate the synergistic inhibition of mycotoxigenic fungi infection on bell pepper fruits by the combination of citronella and lemongrass essential oils (CEO & LEO). A total of 570 fungal isolates were identified from fruit samples collected in six locations in Egypt, among which Mucor sp. and Aspergillus niger were predominant. Seven isolates were found to produce mycotoxins, among which four Aspergillus isolates were aflatoxins producers, and one isolate of each of Alternaria alternate, Fusarium oxysporum and Penicillium expansum produced alterneriol, zeralenone, and patulin toxins, respectively. Gas chromatography–mass spectrometry analysis of CEO and LEO confirmed that the citral compound was the major constituent in both oils. The combination of the CEO and LEO showed antifungal synergistic effects against mycotoxigenic fungi across all tested concentrations under in vitro and in vivo conditions. The combination of CEO and LEO is effective against mycotoxigenic fungi infection in bell pepper fruits.