Submitted to: Meeting, Center for Food Safety, University of Georgia
Publication Type: Abstract Only
Publication Acceptance Date: 1/15/2003
Publication Date: 3/2/2003
Citation: Voss, K.A., Norred, W.P., Meredith, F.I., Riley, R.T., Bacon, C.W., Saunders, D.S. 2003. EFFECTS OF COOKING ON THE BIOLOGICAL ACTIVITY OF FUMONISINS IN CORN. University of Georgia Center for Food Safety Annual Meeting. March 2-3,2003. Atlanta, GA. Interpretive Summary: Abstract - No summary required.
Technical Abstract: Fumonisins are mycotoxins found in corn and corn-based foods. Cooking reduces their concentrations in foods under some conditions, but little is known about how cooking affects their biological activity. Baked cornbread, pan-fried corn cakes, and deep-fried corn fritters were made from corn meal spiked with Fusarium verticillioides culture material (CM) and then fed to male rats (n=5) for 2 weeks at high (1% w/w CM equivalents) or low (0.1% CM equivalents) doses. A control group was fed 1% w/w sound corn. Toxic response to the baked cornbread, pan-fried corn cakes, deep-fried fritters and the CM was similar and included decreased body weight gain (1% diets only), decreased kidney weight, and kidney and liver lesions of the type caused by fumonisins. Fumonisin concentration (fumonisin B1 + B2) in the 1% w/w pan-fried corn cake diet (92 ppm) was slightly lower than those of the 1% w/w baked cornbread (132 ppm), deep-fried fritter (120 ppm) and CM (130 ppm) diets. In another experiment, corn, masa made from the corn, and tortilla chips made from the masa were extracted with acetonitrile/water (1:1). The extracts were dried and redissolved in DMSO. Vero cells were then dosed with 4 microL of the redissolved extracts for 48 hr. The corn extract inhibited ceramide synthase activity (a fumonisin-specific effect) as shown by a significant increase in the concentration of the enzyme substrate sphinganine (Sa) (mean=132 pmole/well) in the culture media. In contrast, Sa concentration in the media from cells dosed with the masa, baked chip or fried chip extracts (mean Sa=14-24 pmole/well) remained low. Fumonisin B1 concentrations of the masa and chips (3.6-6.7 microgram/g) were likewise reduced 80-90% compared to the corn (32 microgram/g). In summary, baking and frying had no significant effect on the biological activity or the concentration of fumonisins in corn-based foods, whereas nixtamalization reduced both biological activity and fumonisin concentration in masa. These bioassays provided no evidence for the formation of unknown, biologically active fumonisins during cooking.