Aflatoxin Contamination in the Maize Supply Chain: A Case of Nampula Province, Mozambique

Aflatoxin contamination in maize remains a major food safety and public health concern in Nampula Province, Mozambique. Maize samples obtained from farmers, traders, and milling units across the districts of Malema, Mossuril, Mecuburi, Monapo, and Nampula in 2024 and 2025 were analysed using UPLC-ESI-MS/MS. In 2024, aflatoxins were detected in samples from Mecuburi (43%), Mossuril (17%), Monapo (17%), and traders (13%), with some exceeding the regulatory limit of 15 µg/kg. AFB₁ was the predominant aflatoxin, followed by AFB₂. At the farmer level, Mecuburi recorded the highest contamination, with AFB₁ and AFB₂ detected in 43% of samples and AFG₁ and AFG₂ in 29%, while Mossuril had 20% contamination with AFB₁ and AFG₁. The maximum concentration was 4221.33 µg/kg of AFB₁ in Mecuburi, whereas the minimum detected concentration was 2.82 µg/kg of AFB₂. Aflatoxins were not detected above the limit of detection in milling samples or in samples collected in 2025. Despite the relatively low prevalence, the occurrence of extremely high aflatoxin concentrations highlights persistent contamination risks and the need for integrated mitigation strategies throughout the maize supply chain.