Location: Toxicology & Mycotoxin ResearchTitle: Reduction of fumonisin B1 in corn grits by twin-screw extrusion Author
|Voss, Kenneth - Ken|
Submitted to: Journal of Food Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/13/2011
Publication Date: 9/14/2011
Publication URL: http://naldc.nal.usda.gov/download/54056/PDF
Citation: Jackson, L.W., Jablonski, J.E., Bullerman, L.B., Bianchini, A., Hanna, M.A., Voss, K.A., Hollub, A.D., Ryu, D. 2011. Reduction of fumonisin B1 in corn grits by twin-screw extrusion. Journal of Food Science. 76(6):150-155. Interpretive Summary: Fumonisins are toxins produced by molds found in corn. Fumonisin B1 (FB1) is the most common. It causes animal diseases and, although its impact on human health is unclear, evidence suggests that FB1 increases the risk of certain cancers and birth defects. Therefore, minimizing exposure to FB1 and other fumonisins is desirable. Extrusion is a cooking process that combines high heat and pressure. To determine its effectiveness to reduce fumonisin concentrations, two batches of food grade grits containing 10 or and 50 µg/g FB1 (and lesser amounts of fumonisins FB2 (FB2) and B3 (FB3)) were cooked using a twin-screw extruder. Glucose was added to one of the batches prior to cooking. Extrusion without glucose reduced FB1 concentrations 64-72% and greater reductions of 89-94% were achieved when glucose was present. Extrusion also reduced FB2 and FB3 concentrations by 26-73%, while FB2 and FB3 were reduced more than 89% in the grits cooked with glucose. Other FB1 reaction products were also identified in the cooked grits. N-(deoxy-D-fructos-1-yl)-FB1 which is formed when glucose combines with FB1, accounted for 38-46% of the total FB1 measured in the grits extruded with glucose. Twenty-three to 37% of the FB1 found in the extruded products (with or without glucose) were bound to matrix components such as protein or starch and only minor amounts of FB1 were recovered as a hydrolyzed FB1 reaction product. Unknown products were also formed as only 46% of the grits originally present before cooking were accounted for. These results show that extrusion cooking using a twin-screw extruder reduces fumonisins in corn grits and that reduction is increased further with the addition of glucose to the grits before cooking. Additional studies are needed to identify unknown fumonisin reaction products formed during extrusion.
Technical Abstract: Fumonisins are mycotoxins found in corn and corn-based foods. Fumonisin B1 (FB1), the most common, causes animal diseases and there is evidence suggesting that it increases the risk of certain cancers and birth defects in humans that are highly dependent on contaminated corn as a diet staple. Therefore, minimizing exposure to fumonisins, especially FB1, is desirable. The chemical fate of fumonisins in flaking corn grits during extrusion cooking was investigated by measuring fumonisin B1 (FB1) and its analogs in the grits prior to and after processing. Food grade grits and two batches of grits contaminated with FB1 at 10 and 50 µg/g after fermentation with Fusarium verticillioides were processed with or without glucose supplementation (10%, w/w) using a twin-screw extruder. Extrusion reduced FB1 concentrations of the contaminated grits by 64-72% (dry weight basis) in the absence of added glucose and 89-94% with glucose supplementation. Extrusion alone also reduced the concentrations of fumonisins B2 and B3 26-73%, while the concentrations of these less common fumonisins were reduced >89% in grits containing 10% glucose. The mass balance analysis revealed that 38-46% of the FB1 species found in grits after extrusion with glucose was the glucose reaction product N-(deoxy-D-fructos-1-yl)-FB1, while 23-37% of the FB1 species in extruded grits, either with or without glucose supplementation, became bound to grits matrix components during processing. The hydrolyzed form of FB1 was not detected in the raw grits but was found as a minor species in the extruded products, representing <15% of the total FB1 species. These results indicate that extrusion processing using a twin-screw extruder reduces fumonisins in corn grits and that reduction is increased further with the addition of glucose to the grits before cooking. However, less than 46% of the FB1 that was originally present in the uncooked grits was accounted for after processing. Additional research is needed to identify unknown fumonisin reaction products that form during extrusion processing.