Aflatoxin M₁ in raw milk and aflatoxin B₁ in feed from household cows in Singida, Tanzania

ABSTRACT

Aflatoxin M₁ (AFM₁) contamination in raw milk from household cows fed with sunflower seedcakes or sunflower-based seedcake feeds was determined in 37 milk samples collected randomly from different locations in Singida region, Tanzania. Aflatoxin B₁ (AFB₁) contamination in sunflower-based seedcake feed was determined in 20 feed samples collected from the same household dairy farmers. The samples were analysed by RP-HPLC using fluorescent detection after immunoaffinity column clean-up. Recoveries were 88.0% and 94.5%, while the limits of detection (LOD) were 0.026 ng mL⁻¹ and 0.364 ng g⁻¹ for AFM₁ and AFB₁, respectively. Of the analysed cow’s milk samples, 83.8% (31/37) contained AFM₁, with levels ranging from LOD to 2.007 ng mL⁻¹, exceeding both the European Commission (EC) and Tanzania Food and Drug Authority (TFDA) limit of 0.05 ng mL⁻¹. Of the contaminated samples, 16.1% exceeded the Codex Alimentarius limit of 0.5 ng mL⁻¹. AFB₁ was present in 65% (13/20) of the feed samples with levels ranging from LOD to 20.47 ng g⁻¹, 61.53% exceeding the TFDA and EC maximum limits of 5 ng g⁻¹ for complete dairy animal feed. The observed AFM₁ and AFB₁ contamination necessitates the need to raise awareness to dairy farmers in Tanzania to safeguard the health of the end-users.

KEYWORDS:

• Aflatoxin M₁
• cow’s milk
• aflatoxin B₁
• feed
• Singida
• Tanzania

Acknowledgements

The authors are grateful to the Tanzania Food and Drug Authority (TFDA) for supporting sample analysis in their laboratories and highly appreciate the technical assistance of both TFDA and the University of Dar es Salaam staff.

Disclosure statement

No potential conflict of interest was reported by the authors.