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Application of enzyme extraction for fumonisin B(1) in extruded corn grits. A. CHAWNUA, R. L.
Wehling, C. Munimbazi, S. H. Chung, and L. B. Bullerman. University of Nebraska, Dept. of Food Science
& Technology, Lincoln, NE 68583.
A liquid chromatographic method for determining Fumonisin B(1) in
extruded corn grits was developed, using an enzyme digestion procedure with a fungal alpha-amylase to
facilitate the extraction of FB(1) from an extruded corn matrix. Enzymatic digestion conditions were
selected to maximize FB(1) recovery. Digested samples were extracted using acetonitrile/water (50:50), and
then cleaned up using strong anion exchange (SAX), or C(18) solid phase extraction (SPE) cartridges. The
efficiencies of clean-up by these two SPE procedures were compared. FB(1) was measured by precolumn
derivatization with o-phthalaldehyde, followed by isocratic separation on a C(18) reversed-phase column.
The amylase treatment increased recovery of FB(1) approximately 40% when compared to recoveries
obtained from samples without enzyme treatment, yielding a mean recovery of 88.1%. The coefficient of
variation for replicate samples ranged from 7.94% to 11.63%. Baseline resolution of FB(1) was achieved
when extracted samples were pre-treated with the SAX cartridges, and FB(1) was separated using a
micro-Bondapak C(18) analytical column. The method quantitation limit for FB(1) in extruded corn was 62.5
ng/g. The study showed that enzyme treatment freed FB(1) from complex corn matrices before extraction,
and improved the FB(1) recovery.
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