Mycotoxin contamination in peanuts (Arachis hypogaea L.) at post-harvest stage in eastern Ethiopia

Peanuts are highly susceptible to contamination by toxigenic fungi and associated mycotoxins during both pre- and post-harvest stages. In Ethiopia, data on mycotoxin levels in peanuts remain limited. This study aimed to investigate the occurrence and concentrations of mycotoxins in post-harvest peanut samples (N = 54) collected from January to March 2023 from the 2022 harvest season in Babile and Fedis districts, as well as the surrounding areas of Harar town. All samples were analyzed for 23 mycotoxins, including aflatoxins (AFB1, AFB2, AFG1, and AFG2), fumonisins (FB1, FB2, and FB3), ochratoxin A (OTA), and sterigmatocystin (STERIG), amongst others, using LC-MS/MS. About 61% of samples were contaminated with at least one mycotoxin, with up to six different mycotoxins detected in a single sample. The highest contamination was observed in samples from the Harar area, where nine mycotoxins were detected. Samples from Babile and Fedis were also contaminated with up to seven mycotoxins. Harar samples contained the highest levels of AFB1 (4222 µg/kg), AFB2 (3497 µg/kg), and OTA (178 µg/kg). Babile had the highest concentrations of AFG1 (3136 µg/kg) and AFB1 (2483 µg/kg), while Fedis showed the highest AFG2 (106 µg/kg). Fumonisin levels (FB1–FB3) were low overall (2.2–37.0 µg/kg). This is the first report confirming the presence of fumonisins, OTA, and STERIG in Ethiopian peanuts. Overall, the findings highlight substantial contamination with multiple mycotoxins, particularly AFs and OTA, posing a significant public health risk. The study underscores the urgent need for comprehensive food safety interventions across Ethiopia’s peanut production and supply chain.