Abstract
| - The present study aimed to analyze the mycoflora and the occurrence of alternariol (AOH) andalternariol monomethyl ether (AME) in grain samples of sunflower during different stages of plantdevelopment in Nova Odessa, State of São Paulo, Brazil. The data obtained were correlated withthe presence of fungi in soil, wind-dispersed fungi, and the predominant climatic conditions of theregion where the experiment was carried out. Analysis of the mycoflora revealed the presence ofFusarium verticillioides and Alternaria alternata in 70% and 46% of the samples, respectively. Theprofile of wind-dispersed fungi also showed F. verticillioides as the most frequently isolated fungus(68%), although A. alternata was detected in 28% of samples. In soil, Penicillium was the most frequentspecies (49.9%), followed by F.verticillioides (47.7%) and A. alternata (10.9%). Regarding wateractivity, sunflower grains presenting a high frequency of isolation of F. verticillioides and A. alternatahad a water activity ranging from 0.92 to 0.96, and statistical analysis revealed a negative linearcorrelation between the isolation of fungi and water activity. HPLC analysis showed that 18% of thesunflower grains were contaminated with alternariol (24.9−170.9 ng/g) and 10% with alternariolmonomethyl ether (14.1−108.6 ng/g). The contamination of sunflower grains with AOH and AME inthe field was low when compared to the LD50 necessary to cause toxicity to animals. However, thecontamination with other toxigenic fungi such as F. verticillioides may indicate the presence of othermycotoxins in sunflower grains and a possible synergistic effect between them. This is the first reportof the natural occurrence of alternariol and alternariol monomethyl ether in sunflower grains in Brazil. Keywords: sunflower; alternariol; alternariol monomethyl ether; mycoflora
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