Aspergillus species as mycotoxin producers in agricultural products in central Europe
Authors: Kocube Sandor , Varga Janos , Sigeti Djendji , Baranji Nikolet , Suri Katalin , Tot Bela , Toldi Eva , Bartok Tibor , Mesterhazi Akos 
Published: May 2013

Aspergillus species are able to produce a range of mycotoxins, includ?ing
e.g. aflatoxins, ochratoxins, fumonisins and patulin. Aflatoxins are mainly
produced by members of Aspergillus section Flavi, and they contaminate
various agricultural products in several parts of the world. Several recent
reports have indicated that aflatoxin-producing fungi and consequently
aflatoxin contamination occur in agricultural commodities in a number of
European countries which have not been faced with this problem before.
Indeed, recent surveys have clarified that concentrations of aflatoxins in
maize products and milk has been exceeding the EU limit in several regions of
Central Europe including Serbia, Slovenia, Croatia, Northern Italy and
Romania. However, aflatoxin contamination and aflatoxin-producing Aspergillus
species have not been identified yet in maize in Hungary. We examined the
presence of potential aflatoxin-producing Aspergilli in maize samples
collected in southern parts of Hungary. Several A. flavus isolates were
identified, and pre?liminary results indicated that some of the isolates were
able to produce aflatoxins. Con?tamination of other agricultural products
with aflatoxins can also pose problems in Central Europe due to global
warming. Ochratoxin contamination of grapes and grape-derived products is
usually caused by black Aspergilli, especially by A. carbonarius and A.
niger, although these species have been rare in Central European vineyards
due to climatic fac?tors. Ochratoxin contamination of other agricultural
products including spices and cereals was also observed in the region.
Besides, ochratoxin producing Aspergilli are frequently isolated from
imported products including coffee beans, dried fruits and spices, and
ochra?toxin contamination of these samples was also observed. Fumonisins are
produced mainly by Fusarium species, and by the recently identified producers
Aspergillus niger and A. awamori. We examined fumonisin producing abilities
of A. niger / A. awamori isolates col?lected from the variety of substrates
including raisins, figs, dates, maize and onions. The isolates, which came
from dried vine fruits, produced several fumonisin isomers also pre?sent in
the raisin samples, indicating that fumonisin contamination of these products
was probably caused by black Aspergilli. Besides, strains collected from
figs, dates and onions were also able to produce fumonisins, and preliminary
data indicated that figs and onions were also contaminated with low but
significant amount of fumonisins. Potential fumonisin producing A. awamori
isolates were also identified on maize samples. Further studies on the
examination of the occurrence of fumonisins and their potential producers in
other agricultural products are in progress. Regarding patulin, contamination
of apple based products is a serious problem in the region, mainly caused by
Penicillium species. Although patulin producing Aspergilli have also been
identified in cereals, patulin contamination of cereals and cereal based
products is usually low in Central Europe.