Prevention of aflatoxin contamination of maize by Aspergillus flavus through aqueous plant extracts in Saudi Arabia

The efficacy of four concentrations of aqueous extracts of 11 local plants in the management of Aspergillus flavus and aflatoxin contamination was investigated by measuring the dry weight of A. flavus. The extracts of Allium sativum gave the best results, decreasing the dry weight of the fungus, followed by Aloe vera, whereas 20%Coriandrum sativum extract had no significant effect on the fungal dry weight. Aqueous 20% extracts of the herb Thymus vulgaris and the rhizome of Zingiber officinalis most strongly inhibited aflatoxin production for B1 (79.1%), followed by the leaf extracts of Olea europaea and Eucalyptus globulus (75.0%), although the effect on A. flavus growth was moderate. The herb T. vulgaris and extract of Ocimum basilicum leaf showed the strongest inhibition of B2 (76.2%). Conversely, the leaf extracts of Zizyphus spina andCassia italica produced only marginal effects on the percentage of inhibition of aflatoxins B1 and B2. No positive correlation was observed between mycelial growth and aflatoxin production in A. flavus.   Key words: Maize, Aspergillus flavus, aflatoxin, aqueous plant extracts.