Mycoflora, Aflatoxin Occurrence, and Consumer Risk Assessment in Marketed Groundnuts from Kinshasa (Democratic Republic of the Congo) and Minna (Nigeria)

Abstract

Aflatoxins, a group of highly toxic mycotoxins primarily produced by Aspergillus flavus and Aspergillus parasiticus, are common contaminants of groundnuts, particularly in subtropical regions. These toxins cause hepatocellular carcinoma (HCC), a type of liver cancer that ranks among the leading causes of cancer-related deaths worldwide, with a disproportionate impact on populations in developing countries, like SSA. This study aimed to assess the risk of aflatoxin exposure and estimate the HCC risk for populations in the Democratic Republic of the Congo (DRC) and Nigeria when eating groundnut. A total of 256 groundnut samples were collected from local markets in Kinshasa (DRC) and Minna (Nigeria). The fungal load, contaminating fungal species, and their occurrence were determined using standard microbiological techniques. Aflatoxin contamination levels were quantified using ultra-high-performance liquid chromatography (UHPLC). Risk characterisation was performed using the Margin of Exposure (MoE) approach, and the population-level HCC potency was also estimated using the standard protocol. The results revealed Aspergillus as the most prevalent fungal genus, followed by Penicillium, Fusarium, and Alternaria. A significant difference (p < 0.05) was observed in fungal loads between groundnuts from Kinshasa (14.4 x 10² CFU/g ± 1.92) and Minna (7.4 x 10² CFU/g ± 1.14). Aflatoxin contamination levels, with groundnuts from Kinshasa showing significantly higher levels (151.80×10³ ng/kg ± 47.62) compared to those from Minna (14.20×10³ ng/kg ± 1.55). The MoE indicated a potential health risk. The estimated HCC cases attributable to aflatoxin exposure were approximately 514,000 in the HBsAg+ Congolese population (8%) and 62,000 in the Nigerian population (13%).