Bioaccessibility of total bound fumonisin from corn flakes.

Fumonisin B1 (FB1) is often found as a natural contaminant of corn and corn-based food. Several publications have demonstrated the presence of fumonisin bound to proteins and to other compounds of the matrix. In spite of the low oral bioavailability of FB1 in rats, pigs, chickens, cows, and monkeys, FB1 can cause agriculturally significant disease and possibly human cancer. The aim of this work was to determine the bioaccessibility of total bound FB1 (TB FB1) (percentage of TB FB1, released from corn flakes to the chyme) after in vitro digestion. Two samples of corn flakes washed with solvents were incubated with gastrointestinal tract solutions simulating saliva plus stomach and duodenal juices. After hydrolysis of the chyme with KOH, TB FB1 was determined as hydrolyzed FB1 (HFB1). The bioaccessibility of TB FB1 in chyme from corn flakes was 37-64%, indicating that these derivatives should be considered in evaluation of exposure to fumonisin.