Evaluation of the intestinal absorption of deoxynivalenol and nivalenol by an in vitro gastrointestinal model, and the binding efficacy of activated carbon and other adsorbent materials.

In vitro screening of 14 adsorbent materials, including some commercial products used to detoxify Fusarium-mycotoxins, were tested in the pH range of 3-8 for deoxynivalenol (DON)- and nivalenol (NIV)-binding ability. Only activated carbon showed to be effective with binding capacities of 35.1 micromol and 8.8 micromol DON and NIV/g adsorbent, respectively, calculated from the adsorption isotherms. A dynamic laboratory model simulating the gastrointestinal (GI) tract of healthy pigs (TIM system) was used to evaluate the small-intestinal absorption of DON and NIV and the efficacy of activated carbon in reducing the relevant absorption. The in vitro intestinal absorptions of DON and NIV were 51% and 21%, respectively, as referred to 170 microg DON and 230 microg NIV ingested through contaminated (spiked) wheat. Most absorption occurred in the jejunal compartment for both mycotoxins. The inclusion of activated carbon produced a significant reduction in the intestinal mycotoxin absorption. At 2% inclusion level the absorption with respect to the intake was lowered from 51% to 28% for DON and from 21% to 12% for NIV. The binding activity of activated carbon for these trichothecenes was lower than that observed for zearalenone, a mycotoxin frequently co-occurring with them in naturally contaminated cereals.