Determination of Deoxynivalenol and Total Aflatoxin Levels in Commonly Traded Grains in The Commercial City of Katsina-Ala North-Central Nigeria

Abstract

This study determined the total aflatoxin and deoxynivalenol levels in grains traded in the commercial city of Katsina-Ala, North-Central Nigeria, from 300 samples obtained from 30 composites, of 10 different locations, using the direct competitive Enzyme Linked Immunosorbent Assay (ELISA). Moisture content, total aerobic microbial count, mould count, coliform and Escherichia coli were determined using standard analytical methods. Mycotoxins were detected in all samples across the study locations; total aflatoxin ranged from 2.30 to 8.4 ppb, which were within the maximum limits for aflatoxins, deoxynivalenol (DON) concentration ranged from 2,900.00 to 8,400.00 ppb that was above the maximum limits. Moisture was high in all samples with content ranging from 9.0279 to 12.3851 %, microbial contamination was observed on the grains. It was also observed that, these grains were more predisposed to DON than aflatoxin, thus vulnerability of the grains to DON was in the order: sorghum > maize > millet, whereas total aflatoxin level was in the order: sorghum > millet > maize respectively. Pearson’s 2-tailed correlation at 0.05 level of significance revealed strong correlation of deoxynivalenol with moisture content across locations, while ANOVA at 5 % level of significance established the presence of mycotoxins and their precursors across the locations. This fundamentally, showed microbial tainting of these cereals in the study location indicating that farmers and marketers handle these grains in an unhygienic manner.