|Saunders, D. Stephen|
Submitted to: US-Japan Coop Pgm on Dev and Util of Natural Products Abstracts Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 10/20/2002
Publication Date: 11/11/2002
Citation: Voss, K.A., Norred, W.P., Meredith, F.I., Riley, R.T., Bacon, C.W., Saunders, D. 2002. DETERMINING THE EFFECT OF BAKING, FRYING AND MIXTAMALIZATION ON FUMONISINS BY MEANS OF IN VIVO AND IN VITRO BIOASSAYS. US-Japan Coop Pgm on Dev and Util of Natural Products Abstracts Proceedings. November 11-15,2002. Emoryville, CA.
Interpretive Summary: Abstract only.
Technical Abstract: Fumonisin mycotoxins are found in corn and corn-based foods. Cooking decreases fumonisin concentrations under some conditions, but little is known about how cooking affects its 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. Controls were fed 1% w/w sound corn. Toxic response to baked cornbread, pan-fried corn cakes, deep-fried fritters and the CM included decreased body weight gain (1% diets only), decreased kidney weight, and microscopic kidney and liver pathology 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, but not significantly (p<0.05) lower than those of the 1% w/w baked cornbread (132 ppm), deep-fried fritter (120 ppm) and CM (130 ppm) diets. In a second experiment, 10 g of corn, masa made from the corn, and tortilla chips made from the masa were extracted twice with 50 ml acetonitrile/water (1:1). Extracts were combined, dried, and redissolved in 1.0 ml DMSO. Vero cells were dosed with 4 µl of the redissolved extracts for 48 hr. The corn extract inhibited ceramide synthase as indicated by significantly increased cell sphinganine (Sa) concentrations (mean=132 pmole/well), whereas Sa was unaffected by the masa, baked chip and fried chip extracts (mean Sa 14-24 pmole/well). Fumonisin B1 concentrations of the masa and chips (3.6-6.7 µg/g) were likewise reduced 80-90% compared to the corn (32 µg/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. Importantly, these bioassays provided no evidence for the formation of unknown, biologically active fumonisins during cooking.