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Stability of mycotoxins in thermally processed corn products

Mauricio Montoya Castelo, University of Nebraska - Lincoln

Abstract

Because of the lack of a suitable analytical method for quantification of moniliformin (MON) in thermally processed corn products, development of an enzyme linked immunosorbant assay (ELISA) was investigated. A moniliformin-adipic dihydrazide-bovine serum albumin (MON-ADH-BSA) conjugate was prepared and used as antigens to produce polyclonal antibodies against MON in rabbits. Good antibody titers were found in the two rabbits sera tested. The concentration causing 50% inhibition of binding (CI50) of the polyclonal antibodies to the solid phase MON-ADH-Keyhole limpet hemocyanin (KLH) by MON was 3.5 m g/ml. Stability of aflatoxin B1 (AFB1), aflatoxin B2 (AFB2) and moniliformin (MON) in spiked and cultured flaking grits during a simulated corn flake process were investigated. No significant differences in aflatoxin concentrations were found when flaking grits were processed with and without sugars. Significant losses of aflatoxin were found in both spiked (77% AFB1, 82.2% AFB2) and cultured grits (85.3% AFB1). Corn flake processing resulted in small, but statistically significant (p < 0.05), losses of MON in spiked and cultured grits, up to 27% and 36%, respectively. Extrusion cooking of spiked corn grits with MON (5 m g/g) at different temperatures (140, 160, 180 and 200°C) and screw speeds (40, 80, 120 and 160 rpm) resulted in small losses of MON (up to 34%). Corn grits spiked with fumonisin B1 (FB1) (5 m g/g) and extrusion cooked with different parameters, sugar type, and sugar concentration significantly affected the loss of FB1. Greater losses of FB1 were found when corn grits were extrusion cooked in the presence of glucose (44.8–66.7%) than with fructose (32.4–53.2%) or sucrose (26–42.7%). In the same study, extrusion cooking of corn grits at higher glucose concentrations and lower screw speeds resulted in greater losses of FB1 (up to 92.7%). As expected, corn flake processing of both spiked and cultured flaking grits with glucose and glucose in combination with maltose and high fructose corn syrup resulted very effective in reducing FB1 concentrations. ^

Subject Area

Agriculture, Food Science and Technology|Chemistry, Agricultural

Recommended Citation

Castelo, Mauricio Montoya, "Stability of mycotoxins in thermally processed corn products" (1999). ETD collection for University of Nebraska - Lincoln. AAI9947120.
http://digitalcommons.unl.edu/dissertations/AAI9947120

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