The distribution of Fusarium molds and fumonisins was determined in commercial and experimental dry‐milled corn fractions. Fusarium infection of the commercial whole corn samples ranged from 10 to 28%; F. moniliforme was the predominant species. Fusarium counts in corn fractions were <100 colony‐forming units (CFU)/g in flaking grits, <100 ‐ 6.4 × 104 CFU/g in bran, <100 − 1.6 × 104 CFU/g in germ, and <100 − 2.7 × 103 CFU/g in flour. Fumonisin concentrations were ≤0.1 μg/g in flaking grits, 0.2–1.1 μg/g in flour, 0.1–2.0 μg/g in germ, and 1.5–3.2 μg/g in bran. Yellow, blue, and white dent corns naturally contaminated with varying levels of fumonisins (25.4, 3.9, and 0.3 μg of fumonisin B1 per gram) and Fusarium molds (3.9 × 106, 8.0 × 105, and 2.6 × 104 CFU/g) were experimentally dry milled with a horizontal drum degermer. Number 5 grits contained significantly lower Fusarium counts and fumonisin concentrations than the whole kernel corn. Fusarium counts and fumonisins increased as grit size decreased, and high Fusarium counts and fumonisin concentrations were found in germ, bran, and fines.

Fumonisins are mycotoxins produced primarily by Fusarium moniliforme and Fusarium proliferatum in corn. Fumonisins have been implicated as the causal agents in a variety of animal diseases and are epidemiologically linked to the high incidence of human esophageal cancer in some regions of the world. Little is known about the effects of common processing methods on the fumonisin content of food. The objective of this study was to determine the effects of baking and frying on the stability of fumonisin B1 (FB1) spiked into corn-based foods. Baking corn muffins spiked with 5 μg/g (dry weight basis) FB1 at 175 and 200 °C for 20 min resulted in 83.7 ± 3.5% and 72.4 ± 5.9% retention of FB1, respectively. At both temperatures, losses of FB1 were significantly (p < 0.05) greater at the surface than at the core of the muffins. No significant losses of FB1 were found when spiked corn masa was fried at 140−170 °C for 0−6 min. FB1 began to degrade at frying temperatures ≥180 °C and times ≥8 min. Frying chips for 15 min at 190 °C resulted in 67% loss of FB1. These processing studies suggest that fumonisins are heat stable compounds that survive under most conditions used during baking or frying. Keywords: Fumonisin B1; processing; frying; baking; heating; decomposition

Cereal Chem. 76(1): [16][17][18][19][20] Corn grits spiked with fumonisin B 1 (FB 1 ) at a level of 5 µg/g were extrusion cooked in a corotating twin-screw extruder at different temperatures (140, 160, 180, and 200°C) and screw speeds (40, 80, 120, and 160 rpm). Good recoveries of FB 1 were obtained from the nonextruded as well as the extruded grits by using high-performance liquid chromatography. Both the barrel temperature and the screw speed significantly (P ≤ 0.05) affected the extent of fumonisin reduction in extruded grits.As expected, the FB 1 recovered decreased with an increase in temperature and a decrease in screw speed. The amount of FB 1 lost from cooking grits at the different extrusion parameters used in this study ranged from 34 to 95%. About 46-76% of the spiked FB 1 was lost when the grits were cooked at temperatures and screw speeds that resulted in acceptable product expansion and color.