NATURAL OCCURRENCE OF DEOXYNIVALENOL IN SOYBEAN GROWN IN SERBIA - Soybean and Wheat Crops: Growth, Fertilization, and Yield - page 106

aflatoxin registered Jacobsen et al. [18] and Beg et al. [19]. The former authors registered
aflatoxin B 1 in hulls in only three of 24 samples with the largest content detected being 5.8
μg/kg, whereas the latter authors found only 0.20 μg/kg (range 0 - 1.27 μg/kg). However, the
presence of aflatoxin in soybean in significantly higher concentrations was registered by Jajić
et al. [20]. Also, it has been observed that 100% of the soy-based infant cereals (containing
corn or rice as the probable sources of aflatoxin) had a detectable level of aflatoxin B 1 [21]. A
survey of the pertinent literature shows that ochratoxin presence in soybean has not been
identified frequently [18] or its content was relatively low 4.6 - 9.6 μg/kg [19] in contrast to
soy-based product, probably because of the presence of other grains [22].
Relatively little information exist about the occurrence of Fusarium toxins in soybean
and soybean meal. Thus the in vitro formation of HT-2 toxin, T-2 toxin, T-2 tetraol,
neosolaniol and/or ZEA by Fusarium strains with soybeans as substrate was reported by
Richardson et al. [23]. These authors suggested soybean products to present a mycotoxic
hazard which warrants attention. In native beans as well as in some products used in
agricultural practice trichothecenes and ZEA were detected by Jacobsen et al. [18], Jajić et al .
[20], Clear et al. [24], Rafai et al . [25], Sokolović and Šimpraga [26] and Schollenberger et
al. [27]. The occurrence of Fusarium toxins in soy-based foodstuffs was studied by Lombaert
et al. [22], Scott [28] and Schollenberger et al . [29].
The legislations of some ten countries prescribe explicitly the maxumal allowed content
of aflatoxins B 1 , that is B 1 , B 2 , G 1 and G 2 for soybean and soybean products used as food and
feed, whereas these quantities for ZEA and ergot are defined only in two countries each [30].
Advisory levels of 500 μg/kg of DON were passed by the European Union [31] for bread,
cakes, biscuits, cereal-based snacks and breakfast cereals.
In view of all the above the aim of this study was to gain an insight into the presence of
DON in soybean grown in Serbia during 2004-2007.
E XPERIMENTAL
Chemicals
All solvents used for the DON extraction from soybean and soybean meal samples, as
well as for the mobile phase preparation, were of HPLC grade. All chemicals used in the
investigation were of reagent grade. Solutions were prepared in doubly deionized water
except when stated otherwise.
DON standard solutions. DON (Biopure, Tulln, Austria) was purchased as an analytical
standard. Calibrant solution was prepared in ethyl acetate-methanol (19:1, v/v) at the
concentration of 0.1−0.2 mg/ml from crystalline substance according to AOAC method
986.17. Stock solution was prepared by measuring 1.00 ml of calibrant solution of DON into
a 5 or 10 ml volumetric flask and diluting to volume with ethyl acetate-methanol (19:1, v/v).
Working calibrant solutions were prepared by evaporating the appropriate volume of the
stock solution and diluting with 1.00 ml of methanol. Standard solutions were stored at 4 0 C.