Stability and Problems in Recovery of Fumonisins Added to Corn-Based Foods

Abstract

Because the natural occurrence of fumonisins is so far known almost exclusively in corn, we have limited our investigations on their stability to corn-based foods. In these studies, distinction must be made between real losses, binding, and any matrix-related method problems. Fumonisins B1 (FB1) and B2 (FB2) were about 40% recovered when heated in corn meal at 190°C, about 20–30% recovered when heated in moist corn meal at 190°C, and completely unstable in corn meal at 220°C. Average recoveries of FB1 and FB2 added to blank heated matrixes were 69–107% in control experiments. Baking corn meal muffins spiked with 2.5 μg FB1 and FB2/g corn meal at 220°C also resulted in losses of fumonisins. Little or no fumonisins were recovered from corn bran flour when methanol–water (3 + 1) was used as extraction solvent. However, when methanol-borate buffer (pH 9.2) (3 + 1) was used, recoveries averaged 91 ± 17 and 84 ± 9%, respectively, for FB1 and FB2; and natural contamination of the corn bran flour with FB1 and FB2 at levels of 1.9 and 0.95 μg/g, respectively, was revealed. Comparable recoveries were observed for 1 brand of a corn bran breakfast cereal, but the binding effect was not seen with a second brand, for which methanol-water (3 + 1) alone was a good extraction solvent. Recoveries of FB1 and FB2 from a mixed cereal for babies were only about 50% with either extraction solvent mixture. Additives present in the mixed cereal—calcium carbonate, dibasic calcium phosphate, and reduced iron (iron filings)—did not affect recoveries of FB1 and FB2 when added to ground corn or corn flakes, although hydrated ferrous sulfate did.

Effect of Temperature and Screw Speed on Stability of Fumonisin B1 in Extrusion‐Cooked Corn Grits

“…Dupuy et al (1993), however, reported a 50% reduction in FB 1 levels when dry contaminated corn culture material was heated for 10, 30, and 175 min, and 8 hr at 150, 125, 100, and 75°C, respectively. Scott and Lawrence (1994) reported that FB 1 , when heated at 190°C for 60 min, was ≈20% recovered in dry corn meal and ≈42% recovered in moist corn meal. No FB 1 was found after heating the corn meal at 220°C for 25 min.…”

“…Still, these reductions also may be a result of true degradation or increased binding to the matrix during the extrusion cooking process. Differentiation of real losses from problems related to the food matrix is very important (Scott and Lawrence 1994). Nixtamalization of F. proliferatumcultured corn resulted in the hydrolysis of FB 1 to hydrolyzed FB 1 (HFB 1 ), but HFB 1 was still toxic when fed to rats (Hendrich et al 1993).…”

Extrusion Cooking Reduces Recoverability of Fumonisin B1 from Extruded Corn Grits

“…Studies have also shown that the extraction efficiency of fumonisins decreased when 70:30 MeOH:water was used as the extraction solvent (Jackson, 1997;Scott and Lawrence, 1994). The ELISA method used 70:30 MeOH:water as extraction solvent.…”

“…Also >80% of FB 1 and FB 2 were lost at temperatures Ն175°C for 60 min. In another study, FB 1 and FB 2 were reduced by about 60% when heated in corn meal at 190°C for 60 min, by about 70-80% when heated in moist corn meal at 190°C for 60 min, and about 100% in corn meal at 220°C for 25 min (Scott and Lawrence, 1994).…”

Study of the biosynthesis of fumonisins B1, B2 and B3 by different strains of Fusarium moniliforme

“…1992. Methods of decontamination ; Of the six fumonisins known, only fumonisins B1, B2 and Park et al 1992) and destruction by heat (Dupuy et al 1993;B3 (FB1, FB2, FB3) are produced in substantial amounts by Scott and Lawrence 1994) have not yet proved fully satiscultured F. moniliforme (Cawood et al 1991). Since their factory.…”