|Dombrink Kurtzman, Mary Ann|
Submitted to: Journal of Agricultural and Food Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: November 12, 1998
Publication Date: N/A
Interpretive Summary: Fumonisins are toxins produced by certain molds found on corn worldwide. People in Mexico and Central America consume high amounts of corn and may possibly be at risk for exposure to fumonisins. Alkali treatment (nixtamalization) of corn in production of masa and tortillas produces hydrolyzed fumonisins if fumonisins are present in the corn kernels. Masa and tortillas produced in Mexico were analyzed for the presence of fumonisins and hydrolyzed fumonisin. Some of the samples contained 1-2 ppm fumonisin B1, suggesting that fumonisin may be present at rather high levels in the corn before processing or that the pericarp of the corn kernels had only been partially removed. This work represents the first time that nixtamalized products produced in Mexico were examined for fumonisins.
Technical Abstract: Fumonisins, a family of mycotoxins produced by Fusarium moniliforme and F. proliferatum, have been implicated in animal diseases and in areas of South Africa and China where corn is a dietary staple; they have been linked to human esophageal cancer. Inhabitants of Mexico and Central America represent populations who also consume high levels of maize, mainly as products that have undergone nixtamalization (alkali-cooked treatment). Nixtamalized maize products were obtained from Mexico and the United States and were examined to evaluate methods for the detection and quantitation of the different forms of fumonisins. Varying levels of calcium were present in the samples as a result of the processing. The calcium concentrations in the samples ranged from 0.056% to 0.234% so the chelating reagent EDTA (exceeding the calcium concentration by a factor of 1.36) was added to extract the fumonisins. It was expected that the majority of the fumonisin detected would be in the hydrolyzed form, yet the highest level of hydrolyzed fumonisin B1 detected was 0.1 ppm. Detection of 1.0-1.8 ppm fumonisin B1 in some of the Mexican samples of masa and tortillas suggested that fumonisin may be present at moderately high levels in the maize before processing or that the pericarp, where most of the fumonisins are located, had only been partially removed.