Journal of Food Security. 2013, 1(2), 16-26DOI:
Abstract: Lycopersiconesculentum Mill.(tomato) leaves are known to possess antimicrobial activities. In this study, the aqueous fraction containing the antifungal compounds obtained after purification of these leaves extract was evaluated for its effect on proliferation and mycotoxins production by three Aspergillusstrains (Aspergillusfumigatus, Aspergillusflavus and Aspergillusnidulans). This antifungal fraction exhibited a significant inhibition on growth of the three Aspergillusstrains with a dose-dependent manner. Indeed, the radial growth was 90 mm on the medium without antifungal fraction for these three strains, while on the medium at 0.05%, 0.1%, 0.5% and 1% of antifungal fraction, it was respectively 55.67, 40, 20 and 0 mm for A nidulans, 70.67, 50, 24.33 and 0 mm for A. fumigatus and 85.33, 54.67, 24.33 and 0 mm for A. flavus after 7 days of incubation. The absence of conidia germination was also observed only on the medium at 1 % of antifungal fraction for the three strains. This reduction of the growth of the strains when the antifungal fraction content in the medium increased, led to the reduction of mycotoxins production. Indeed, the mycotoxins analysis by Thin Layer Chromatography showed any spots of sterigmatocistin and Gliotoxinin the medium at 0.5% and 1% of antifungal fraction respectively for A. nidulans and A. fumigatus, while for the other concentrations tested, spots of these mycotoxins were observed. For A. flavus, the absence ofthe spot of aflatoxinB1 was observed only in the medium at 1% of antifungal fraction. These results suggest the use of Lycopersiconesculentum leaves extract as a natural fungicide in alternative in chemical fungicides which cause environmental risks.