Aflatoxin Total and Microbial Contamination of Grains, Oil Seeds, Yam Chips and Fish Sold in Maiduguri Market

Abstract

Aflatoxins are secondary metabolites of fungus Aspergillus flavus and closely related species that infects several
agricultural commodities. The consumption of contaminated commodities adversely affects the health of humans
and animals and also a cause of significant economic losses to producers. This study surveyed the aflatoxin
contamination level of cowpea, maize, melon, groundnut, yam chips and fish sold in Maiduguri metropolis.
Samples from each product (250 g) were bulked and thoroughly mixed using coning and quartering method to get
a representative sample for analysis. Laboratory observations were carried out regarding microbial analysis,
proximate composition and aflatoxin content. Samples for aflatoxin detection were classified into three; unsorted
samples, sorted samples and sorted/washed dried samples. Fish had the highest bacterial load 2.48 x 106 cfu/ml and
Aspergillus species were found to be the predominant fungi identified. Maize and groundnut with moisture content
of 5.63 and 5.62 had the highest total aflatoxin contamination (320.51 μg/kg and 236.3 μg/kg respectively) both in
the unsorted group. Total aflatoxin reduction of (58.82 - 99.99%) was observed in all the sorted samples and
sorted/washed dried samples. It can be concluded that commonly sold food in Maiduguri had fungal and Aflatoxin
contamination. Food should undergo several rounds of sorting to remove discoloured grains and grains that shows
evidence(s) of deterioration to reduce the ingestion of food contaminated with aflatoxin.