Fungi Isolation, Identification and Detection of Aflatoxin in Cereals Sold In Major Markets of Katsina Metropolis

Abstract

Aflatoxins are highly toxic and carcinogenic secondary metabolites produced by fungi. The study was aimed at isolating and identifying fungi associated with cereals sold in major markets in Katsina metropolis and detect aflatoxin in the cereals.. Sixteen (16) samples (four each) were collected from four different market namely; Chake, Central, Tsohuwar Kasuwa and Yarkutungu markets. Fungi were isolated and identified using standard microbiological procedures and aflatoxin was detected using thin layer chromatography (TLC). Fungal species isolated and identified were Aspergillus niger, A. flavus, A. parasiticus and A. fumigatus with the occurrence of 6(35.3%), 5(29.4%), 5(29.4%) and 1(5.9%) respectively. Blue florescence which indicated aflatoxin B was detected in the samples with retention factors of 0.52-0.88. Aflatoxin was not detected in the samples having the retention factor above 0.88. This study therefore concluded that cereal samples collected from major markets of Katsina metropolis were contaminated with one or more Aspergillus species and detection of aflatoxin B in some samples is a health hazard. Thus, fungal and aflatoxin contaminations of cereals at the field, during harvest or storage should be controlled through good agricultural, processing and storage practices as well as ensuring hygienic practices at the point of sales.