Isolation Of Mycotoxi genic Fungi And Quantification Of Aflatoxins From Bean Flours Sold In Abeokuta Nigeria

Abstract

The recent increase in consumers’ preference for commercially sold bean flour necessitated the need to determine associated mycoflora and quantify the toxin production by the isolates, since several fungal genera have been associated with bean grains. Four fungal genera were isolated from fifteen beans flour samples sourced from various markets in Abeokuta by serial dilutions and pour plates methods on Potato Dextrose Agar (PDA) plates. Distinct colonies were transferred to Methyl Red Dessicated Coconut Agar (MRDCA) plates to identify toxin- producing isolates and High Performance Liquid Chromatography (HPLC) was used for aflatoxin quantification from the bean flour samples. The isolated fungal genera were, Aspergillus (60%), Fusarium (10%), Rhizopus (15%) and Mucor (5%). Nine of the fifteen samples were found positive for aflatoxigenic organisms and also produced aflatoxins that ranged from 0.006 to 0.151 ng/kg. The presence of toxin- producing organisms in the bean flour which is above the acceptable standard is a red flag that must be addressed vigorously if public health is a priority.