Mycotoxins in maize and breast milk, and the role of pre- and post-harvest practices in 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 methods. Liquid chromatography coupled with tandem mass spectrometry was used to quantify 23 mycotoxins. All of the study families consume maize each day, or 3-6 a week or at least once or twice a week. More (77%) samples in Sidama were contaminated with Fusarium mycotoxin DON than in Jimma (29%) (P<0.001). Similar contamination of fumonisin B1 (19%, Sidama vs. 19%, Jimma), fumonisin B2 (19%, Sidama vs. 18%, Jimma) and fumonisin B3 (12%, Sidama vs.13%, Jimma) contamination were observed (P>0.05). In Sidama, only one sample was contaminated with the Aspergillus mycotoxins aflatoxin B2 and another sample with aflatoxin B1. Of 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 (87%) of respondents in Jimma reported that they removed the maize within one day, which was less practiced (17%) in Sidama. The majority (95%) of the households in Sidama, and some (28%) 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 (100%) households in both zones reported that they sorted visible moldy maize grains before the preparation of maize flour while most (79%, Sidama vs 72%, Jimma) of them reported that they keep the moldy maize for feed. Protective pre- and post-harvest strategies of Fusarium mycotoxins contamination, with a special focus on deoxynivalenol and zearalenone, should be well promoted in the study areas by the agricultural, health and food safety programs as they are possible human and animal health threats.