Control of fumonisin: effects of processing.

Of about 10 billion bushels of corn that are grown each year in the United States, less than 2% is processed directly into food products, and about 18% is processed into intermediates such as high-fructose corn syrup, ethanol, and cornstarch. The vast majority of the annual crop is used domestically for animal feed (60%), and about 16% is exported. Thus, any program for controlling residues of fumonisin (FB) in food must recognize that most of the crop is grown for something other than food. Studies on the effects of wet milling on FB residues found these residues nondetectable in cornstarch, the starting material for high-fructose corn syrup and most other wet-milled food ingredients. Similar effects are noted for the dry-milling process. FB residues were nondetectable or quite low in dry flaking grits and corn flour, higher in corn germ, and highest in corn bran. Extrusion of dry-milled products reduces FB concentrations by 30-90% for mixing-type extruders and 20-50% for nonmixing extruders. Cooking and canning generally have little effect on FB content. In the masa process measurable FB is reduced following the cooking, soaking, and washing steps, with little conversion of FB to the hydrolyzed form. Sheeting, baking, and frying at commercial times and temperatures generally have no effect. In summary, all available studies on the effects of processing corn into food and food ingredients consistently demonstrate substantial reductions in measurable FB. No studies have shown a concentration in FB residues in food products or ingredients.