A true scale study of the maize chain with focus on free and hidden fumonisins and related fungi

The aim of this work was to study the dynamic profile of mycotoxin producing fungi and free and hidden fumonisins into raw maize collected in 28 fields and derived products. The maize bulk was stored in a commercial silo and used for milling. The reliability of the sampling approach, applied in different points at maize harvest-drying, was preliminary tested in this study. Fusarium section Liseola included the prevalent fungi in maize kernels; sampling, in field at harvest and at the storehouse, gave comparable results, while a reduction in fungi colony forming units was noticed after drying, attributed to the thermal treatment. Similar amounts of free and hidden fumonisins were detected, irrespective of the sampling step; this confirmed the reliability of the sampling approach. During silo discharge, till to 10 month storage, a significant decrease resulted both in free and total fumonisins. A significant increase of the free-to-total fumonisins ratio was observed moving from stored kernels to commercial flour, suggesting that milling leads to a reduction of the masked fraction. This result, together with the increase of free fumonisins after maize drying should be considered in future studies.