Investigations on Antifungal Activity of Hemizyga bracteosa (BENTH) Vegetables Extracts against Rice Fungi.

Abstract

Rice is one of the most widely consumed cereals in Benin; its quality and contamination are therefore important factors to take into account for consumer safety. The presence of molds and mycotoxins in rice is one of the main health risks to consider. The objective of this study is to assess the antifungal activities of natural extracts of Hemizygia bracteosa on molds isolated from rice during storage. Volatile and nonvolatile extracts based on the leaves of the plant were produced and the effectiveness of these extracts was tested on five fungal strains. A phytochemical screening was also carried out in order to identify the main families of compounds contained in the nonvolatile extracts of the plant. Yields are 0.003% for essential oils, 7.24% for the aqueous extract, 6.57% for semi-ethanolic extract and 10.72% for the ethanol extract. The minimum inhibition concentrations vary from 3.75 to 37.5 μl/ml. Also tannins,flavonoids, saponins, Quinone derivatives, anthocyanins, leuco-anthocyanins and mucilage have been identified while the hydrocyanic acid derivatives and the anthracenosides was absent. Infestation rates of collected rice samples ranged from 40 to 90% and these extracts have anti-fungal properties found on, Aspergillus parasiticus, A. flavus, A. niger, A. versicolor and Penicillium digitatum.