Occurrence of aflatoxin B1 inTriticum species inoculated withAspergillus flavus

Abstract

Effects of climate change, global trade and technological changes in processing industries cause higher occurrence ofAspergillus flavusand aflatoxin B1(AFB1) in cereal crops. FourTriticumspecies: common wheat (Triticum aestivumL.), spelt (T. aestivumssp.speltaL.), Khorasan wheat (Triticum turgidumssp.turanicumJakubz.) and hybrid wheat (T. aestivumL.– F1) were examined for their response toA. flavusinfection and production of AFB1. The grains were obtained from control and artificially field inoculated wheat withA. flavusisolates (No. 1 and No. 2) in the 2016 vegetation season in the region of Vojvodina (Northern province of Serbia). Spelt wheat showed the strongest response to the infection in comparison to other analysed wheat species due to specific physico-chemical characteristics of the hull. The weakest response toA. flavusinfections was noted in Khorasan wheat. The highest AFB1level (256 μg/kg) was observed in the dehulled spelt grains, in comparison to other species where the AFB1in dehulled grains was not detected. The levels of AFB1in spelt were about three times higher in hulls (648 and 97.3 μg/kg, respectively) in comparison to grains (256 and 30.7 μg/kg, respectively) in two inoculation treatments (A. flavusNo. 1 and No. 2, respectively). In order to investigate the impact of wheat hulls on development ofA. flavus, including the biosynthesis of toxic fungal metabolites, physico-chemical and structural properties of differentTriticumspp. hulls were characterised. The highest value of the water absorption index and total dietary fibre were observed in spelt hulls in comparison to other wheat species. Additionally, the height value distribution of the fossilized stomatal apparatus of hulls indicates the diversity of spelt wheat compared to other wheat species.