Mycotoxins are secondary metabolites from filamentous fungi contaminating food and feed. One major mycotoxin produced by some Fusarium species is zearalenone (ZEN). Due to its estrogen-like structure, ZEN shows strong estrogenic and anabolic effects in addition to immunotoxic and hepatotoxic effects in humans and animals. One pillar of mycotoxin risk management includes effective strategies to eliminate ZEN. The zearalenone hydrolase ZenA (ZENzyme®) can be used for the enzymatic detoxification of ZEN in animal feed to mitigate the negative effects of ZEN on farm animals. ZENzyme® cleaves the lactone ring of ZEN to form the non-estrogenic metabolite hydrolyzed zearalenone (HZEN).

For product registration, the efficacy of ZENzyme® has to be proven to authorities in the form of the reduced systemic absorption of ZEN in the presence of ZENzyme®. Therefore, in a feeding trial, 72 weaned piglets were exposed to feed contaminated with 200 µg/kg ZEN for 42 days. In one group, the feed was additionally supplemented with 10 Units/kg ZENzyme®. For assessment of ZENzyme®’s efficacy, exposure-based biomarkers were measured in plasma, urine, and feces at different time points of the feeding trial by LC-MS/MS. Applied methods did not only cover ZEN, but also the metabolites α-zearalenol (α-ZEL) and β-zearalenol (β-ZEL), as well as the enzymatic degradation products HZEN and decarboxylated hydrolyzed zearalenone (DHZEN). A significant reduction of ZEN in the presence of ZENzyme® was observed in all tested matrices. HZEN levels in feces increased significantly, if ZENzyme® was present in animal feed. DHZEN concentrations above the limit of quantification were scarcely found and most prevalent in urine samples.

These data conclusively showed both the reduction of systemic absorption of ZEN from feed in the gastro-intestinal tract of piglets and the biotransformation of ZEN to HZEN.