Aflatoxins and fumonisin contamination of marketed maize, maize bran and maize used as animal feed in northern Tanzania

Abstract

The objective of this study was to investigate the occurrence of total aflatoxin and total fumonisin in maize and maize-based products in Babati, northern Tanzania. A total of 160 samples were collected in 2013-14. Quantification for total aflatoxin and fumonisin was done using enzyme-linked immunosorbent assay (Reveal AccuScan® Neogen, USA) and the results were confirmed using Liquid Chromatography Tandem Mass Spectrometer. Aflatoxin was detected in 32% of maize samples (mean 3.4 ± 0.3 μg/kg; range 2.1–16.2 μg/kg) and fumonisin in 39% of samples (mean 5.6 ± 1.40 mg/kg; range 0.4–62.0 mg/kg). Among marketed products, maize bran (used for animal feed) was the most contaminated (2.4 μg/kg aflatoxin and 1 mg/kg fumonisin), followed by whole maize in market stalls (1.9 μg/kg aflatoxin and 0.4 mg/kg fumonisin) and then maize flour (1.4 μg/kg aflatoxin and 0.3 mg/kg fumonisin). Un-marketed maize sorted out by farmers as “bad” and intended for animal feeding was the most contaminated (overall mean aflatoxin and fumonisin levels of 1.7 μg/kg and 7.4 mg/kg, respectively). The results indicate that levels of aflatoxin and fumonisin contamination in marketed maize were within tolerable limits.

Keywords: Tanzania, aflatoxins, fumonisins, food safety, maize, market, processors, animal feed