Produced by : Fusarium culmorum, F. graminearum, F. oxysporum, F. roseum, F. moniliforme, F. avenaceum, F. equiseti and F. nivale

Introduction and structure

Zearalenone, a metabolite produced by various species of Fusarium, has been observed as a natural contaminant of cereals, in particular maize, in many countries in Africa and Europe, and in the USA.

Structure of zearalenone and related compounds

Occurrence

Zearalenone has been shown to produce estrogenic effects in animals, and field cases of a specific estrogenic syndrome in pigs and of infertility in cattle have been encountered in association with feed levels of zearalenone of 0.1-6.8 mg/kg and 14 mg/kg, respectively. The compound has also produced congenital malformations in the rat skeleton. In some countries, zearalenone has been found in samples of cornmeal and cornflakes destined for human consumption, at levels up to 70 µg/kg, corresponding to doses 400-600 times lower than those causing effects in monkeys or mice under experimental conditions. In certain areas of Africa, substantially higher levels have occasionally been found in beer and sour porridge prepared from contaminated maize and sorghum.

Effects on human health

No adverse effects due to zearalenone intake have been reported in man, so far, but a possible health hazard connected with the daily intake of zearalenone at levels such as those reported for African fermented preparations needs further attention.

In vivo studies have revealed that zearalenone is rapidly metabolized in animals and humans and eliminated mainly as water-soluble glucuronsides. Free and conjugated forms of zearalenone have been found in the milk of lactating cows under experimental conditions. That high oral doses of the toxin are required to elicit such a response indicates that consumption of contaminated feed by dairy cows would not result in a health hazard to humans.