Aflatoxins, Fumonisins and Zearalenone Contamination of Maize in the Southeastern and Central Highlands Provinces of Vietnam

A survey of the contamination of maize with aflatoxins, fumonisins and zearalenone was carried out in the Southeastern and Central Highland provinces in Vietnam. Four provinces were chosen for sampling maize: Dong Nai (22), Binh Phuoc (25), Dak Lak (30) and Dak Nong (20). Aflatoxin B-1 (AFB(1)), B-2 (AFB(2)), G(1) (AFG(1)), G(2) (AFG(2)), fumonisin B-1 (FB1), fumonisin B-2 (FB2) and zearalenone (ZEA) were analysed by HPLC in 97 maize kernel samples. Fumonisins were the most common toxins found in all samples (67%), followed by aflatoxins (55.7%) and zearalenone (27.8%). The incidence of aflatoxin positive samples (61.7%) in the Southeastern provinces was higher than in the Central Highlands (50%), while fumonisins and zearalenone incidences were higher in the Central Highlands. The mean level of fumonisin B-1 in samples from the Central Highlands provinces (1757 mu g/kg) was significantly greater (p < 0.05) than in the Southeastern provinces (740 mu g/kg). Importantly, the percentage of positive samples (about 70%) that had over 20 mu g/kg (ppb) aflatoxin was very high. Moreover, many samples (53%) contained more than one mycotoxin and this result highlights the difficulty of diagnosing mycotoxicoses in the field and the need for ongoing research to reduce the occurrence of mycotoxins in Vietnamese maize.