Transgenic versus conventional corn: fate of fumonisins during industrial dry milling

The aim of this study was to compare the fate of fumonisins in transgenic and non-transgenic corn during industrial dry milling. For this purpose, whole corn samples and their fractions (germ, pericarp, endosperm, corn meal, and grits) were collected from one of the major Brazilian milling plants, totaling 480 samples. There was no significant difference (p > 0.05) between mean fumonisin (FB₁ + FB₂) levels in transgenic (1130 μg/kg) and non-transgenic (920 μg/kg) whole corn. However, in non-transgenic germ, endosperm and corn meal fraction fumonisin levels were higher (2940 μg/kg, 250 μg/kg and 190 μg/kg, respectively) than in transgenic fractions (2180 μg/kg, 130 μg/kg and 85.0 μg/kg, respectively). Furthermore, the highest percentages of fumonisins were distributed in the germ, corresponding to about 87 and 76% of the total fumonisins present in the whole corn from non-transgenic and transgenic hybrids, respectively. Concerning the endosperm from non-transgenic and transgenic corn, approximately, 23% and 13% of the total fumonisins were retained after the dry milling. Further processing in corn meal (300 to 420 μm particle size) and grits (590 to 1190 μm) decreased the percentages of remaining fumonisins to 4% and 2% (transgenic) and 10% and 3% (non-transgenic corn), respectively. These results suggested that fumonisin concentration was higher in outer and inner non-transgenic fractions when compared to transgenic ones and that the fate of fumonisins during the industrial dry milling could be affected by the transgenic status. However, it was not possible to conclude that the difference was exclusively due to this variable.