Zearalenone: incidence, toxigenic fungi and chemical decontamination in Egyptian cereals.

An investigation was made for the occurrence of Zearalenone (ZEN) and Zearalenone producing fungi in cereals (corn, 50 samples; rice, 45 samples; wheat, 40 samples) collected from Egypt. ZEN was detected in 15 of 50 corn samples with an average concentration of 22.3 ppb. The incidence of ZEN in rice samples was 8.9% (4 samples of 45), and the average was 15.5 ppb. Out of 40 wheat samples 5 samples were contaminated with ZEN (12.5%) with an average of 8.8 ppb. Seventy-nine Fusarium strains belonging to 9 different species were isolated from Egyptian cereals, and when tested for ZEN production only 26 isolates were Zearalenone producer. Efficiency of H2O2 for destruction of ZEN in contaminated corn was studied at different concentration (3, 5 and 10%). The results revealed that per cent of disappearance of ZEN was found to be dependent upon the concentration of H2O2, temperature and period of exposure. The highest per cent of degradation was 83.9%, with 10% H2O2 at 80 degrees C for 16 h, followed by 75% at the same conditions for 8 h, while the lowest one obtained by 3% H2O2 at 50 degrees C for 2 h.