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 of Aspergillus flavus and aflatoxin B1 (AFB1) in cereal crops. Four Triticum species: common wheat (Triticum aestivum L.), spelt (T. aestivum ssp. spelta L.), Khorasan wheat (Triticum turgidum ssp. turanicum Jakubz.) and hybrid wheat (T. aestivum L.– F1) were examined for their response to A. flavus infection and production of AFB1. The grains were obtained from control and artificially field inoculated wheat with A. flavus isolates (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 to A. flavus infections was noted in Khorasan wheat. The highest AFB1 level (256 μg/kg) was observed in the dehulled spelt grains, in comparison to other species where the AFB1 in dehulled grains was not detected. The levels of AFB1 in 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. flavus No. 1 and No. 2, respectively). In order to investigate the impact of wheat hulls on development of A. flavus, including the biosynthesis of toxic fungal metabolites, physico-chemical and structural properties of different Triticum spp. 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.

The effect of storage temperature and water activity on aflatoxin B1 accumulation in hull‐less and hulled spelt grains

“…In our previous study, the same A. flavus isolate (No. 1) produced AFB 1 on an artificial field inoculated spelt up to 256 µg kg −1 in grains, and 648 µg kg −1 in hulls . The results for AFB 1 yield obtained under laboratory conditions were expected to be higher than those reported for AFB 1 spelt H and DHG in the previous field study, that can also be explained by the controlled environmental factors in the laboratory.…”

“…The mycotoxin concentrations of infected grains also showed a high dependence on the wheat species. In comparison to other analysed wheat species, spelt wheat showed the strongest response to the artificial field infection with A. flavus and AFB 1 biosynthesis …”

“…1) obtained from naturally infected grains of common wheat harvested in 2015 in north Serbia was used in this study . The isolate was identified by morphological characteristics and complemented by polymerase chain reaction (PCR) according to the protocol described by Krulj et al The toxigenic potential of the isolate used in the experiment was previously checked …”

“…In comparison to other analysed wheat species, spelt wheat showed the strongest response to the artificial field infection with A. flavus and AFB 1 biosynthesis. 33 The present study was focused on the examination of the effects of different temperature and a w values on the AFB 1 accumulation in hull-less grain (HLG) and hulled spelt grain (H), in order to determine the possible protective effect of hulls. Additionally, the mathematical models [second order polynomial (SOP) and artificial neural network (ANN)] were applied in order to describe the response of the AFB 1 to the tested environmental variables.…”

Spelt vs common wheat: potential advantages and benefits

“…Source: [2] Spelt belongs to the group of the, so called, ancient wheats [3,4]. Among other ancient wheats, emmer and diploid (einkorn) and tetraploid (emmer) wheats.…”