Submitted to: Toxicologist
Publication Type: Abstract Only
Publication Acceptance Date: 11/5/1995
Publication Date: N/A
Technical Abstract: Fumonisins are mycotoxins found on corn and in corn-based feeds and foods. The most common fumonisin, B1 (FB1), is toxic to various species and is a possible contributing factor to human cancer. Masa flour for tortillas is made by nixtamalizing corn, a process which hydrolyses fumonisins. To study the effects of nixtamalization on the toxicity of corn experimentally molded with F. moniliforme (culture material=CM) and to compare the effectiveness of nixtamalization and water extraction for CM detoxification, rats (n=10/group) were fed diets containing 5% weight equivalents of (a) CM, (b) nixtamalized CM (NX), (c) water-extracted CM (WE), or (d) sound corn (SC) (control group) for 4 weeks. Water extraction removed most of the FB1 from the CM; the CM and WE diets contained 71 and 8 ppm FB1, respectively. The NX diet contained 58 ppm hydrolyzed FB1 (HFB1), but no detectable FB1. Body weight gain of the four groups differed significantly (p<0.05) in the order SC>WE>NX>CM. Serum chemical, organ weight, and histopathological findings in CM, NX, and WE-fed groups were consistent with FB1-induced hepato- and nephrotoxicities. Liver lesions were found in all CM and NX-fed rats, but were significantly less severe in the latter group. No significant liver effects were found in the WE-fed group. Nephropathy of similar severity was found in all CM, NX and WE-fed rats. Thus, the in vivo effects of nixtamalized CM containing HFB1 were similar to those of the FB1-containing CM and nixtamalization was less effective than water extraction for reducing the toxicity of FB1-contaminated corn.