Multi-mycotoxin profiling in maize reveals prevalence of Fusarium mycotoxins in South and West Ethiopia

Abstract

Multi-mycotoxin exposure data are missing to guide risk assessment and legislation in Ethiopia. This study therefore aimed to determine mycotoxin contamination levels in maize samples from 176 randomly selected household storages in three agro ecological zones of South (Sidama zone) and West (Jimma zone) Ethiopia, and to examine the post-harvest practices and household processing. Liquid chromatography coupled to tandem mass spectrometry was used to quantify 23 mycotoxins. The majority of the households regularly consumed maize (more than once per day). More (77%) samples in Sidama were contaminated with Fusarium mycotoxins deoxynivalenol than in Jimma (29%) (P<0.001); Similar distributions of fumonisin B1 (19%), fumonisin B2 (19%) and fumonisin B3 (12%, Sidama vs 13%, Jimma) contamination were observed (P>0.05). In Sidama, only one sample was contaminated with the Aspergillus mycotoxin aflatoxin B2 and another sample with aflatoxin B1. From all samples, 40% were contaminated with 3-5 types of Fusarium mycotoxins and only 4% of the samples were contaminated with 6-8 types of mycotoxins. After the harvested maize was dried on the field, the majority of respondents in Jimma reported that they removed the maize within one day, which was less practiced in Sidama. The majority of households in Sidama, and some in Jimma, reported that they dried maize before storage, mainly using the sun. Close to two third of the study participants in the two zones reported that they applied the chemical dichloro-diphenyl-trichloroethane (DDT) during maize storage. All households in both zones reported that they sorted visible mouldy maize grains before preparation of maize flour while most of them kept the mouldy maize for animal feed. Protective strategies of Fusarium mycotoxin contamination, with special focus on deoxynivalenol and zearalenone, should be well promoted in the study areas as they are possible human and animal health threats.