Bioaccessibility and bioavailability of fumonisin B2 and its reaction products with isothiocyanates through a simulated gastrointestinal digestion system

Fumonisins (FBs) are toxins produced mainly by the molds Fusarium verticillioides (also known as Fusarium moniliforme) and Fusarium proliferatum. These mycotoxins are contaminants of wheat, maize, maize-based foods and other grains worldwide. Isothiocyanates (ITCs) are natural compounds produced by the enzymatic hydrolysis of glucosinolates, which are found in plants of the Brassicaceae family. The use of ITCs as food preservatives has been extensively researched. In this study, allyl (AITC), phenyl (PITC) and benzyl isothiocyanates (BITC) fumigation systems (500 μL/L) were employed to reduce FB2 levels naturally produced in bread by Gibberella moniliformis CECT 2987. Reaction products formed between FB2 and ITCs, their bioaccessibility and bioavailability were examined. Reduction of FB2 in bread ranged from 90 to 99%, whereas its bioaccessibility ranged from 57 to 65%. The bioaccessibility found for the FB2-ITCs conjugates ranged from 33 to 71%, whereas the bioavailability of the FB2 and of the FB2-ITCs adducts ranged from 0.6 to 3.0%.