Igor Jajić

Occurrence of Deoxynivalenol in Maize and Wheat in Serbia

A total of 226 samples of maize and 59 of wheat from the 2004–2007 harvests were investigated for the presence and concentration of deoxynivalenol (DON). Samples of the 2004 harvest were analyzed after their storing for one year in barns, while those of the 2005–2007 harvest were taken directly off fields immediately after the harvest. The samples were analyzed by liquid chromatography on an ODS Hypersil column with DAD detector and ELISA methods. The average incidence rate of DON in maize from the 2004 harvest was 50% (concentration range 0.042–2.460 mg/kg, average value 0.536 mg/kg), while for those of the 2005–2007 harvest it was 32.4% (concentration range 0.027–2.210 mg/kg, average value 0.223 mg/kg). In the case of wheat incidence rate of DON for 2004 harvest was 50.0% (concentration range 0.630–1.840 mg/kg, average value 1.235 mg/kg), while for those of the 2005–2007 harvest it was 34.5% (concentration range 0.057–0.423 mg/kg, average value 0.190 mg/kg). Concentrations in two samples of maize and one of wheat (one sample of each cereal being of the 2004 harvest) were above the maximum level adopted by the European Commission. The results obtained were analyzed as a function of climatic conditions and compared with those of the neighboring countries where the relevant data existed.

Aflatoxins contamination of maize in Serbia: The impact of weather conditions in 2015

ABSTRACT In recent years climate changes recorded in temperate regions of Europe have led to aflatoxin (AF) contamination of maize. Thus, the aim of this study was to investigate the influence of weather conditions on levels of aflatoxin B1 (AFB1), aflatoxin B2 (AFB2), aflatoxin G1 (AFG1) and aflatoxin G2 (AFG2) in 180 maize samples collected from the main maize-growing regions (Western Bačka, North Banat, South Banat and Central Serbia) in Serbia after harvest in 2015. The concentrations of AFs were determined by a validated HPLC method with post-column derivatisation and fluorescence detection (HPLC-FLD). The presence of AFB1, AFB2, AFG1 and AFG2 was detected in 57.2%, 13.9%, 5.6% and 2.8% of maize samples in the concentration ranges of 1.3–88.8 µg kg–1, 0.60–2.8 µg kg–1, 1.8–28.5 µg kg–1 and 2.1–7.5 µg kg–1 respectively. The recorded smaller amount of precipitation and especially higher air temperatures during the summer of 2015 were favourable for AF production, which resulted in 32.2% and 21.1% of samples being unsuitable for human consumption, since AFB1 and the sum of AFs concentrations were above 5.0 and 10.0 µg kg–1 respectively. Furthermore, the findings in this study indicate that the microclimate conditions in the investigated regions had a great influence on the contamination frequency of maize with AFs. The highest percentage of samples unsuitable for human consumption, considering both AFB1 and total AFs content were 72.5% and 51.5% respectively from Central Serbia, whilst the lowest percentages of 15.6% and 6.2% respectively were found in Western Bačka. These findings confirmed that maize should be continuously monitored in order to protect human and animal health from the harmful effects caused by AFs contamination.

Presence of deoxynivalenol in small-grain samples from 2009/10 harvest season.

Fusarium head blight (FHB) is present in all growing regions of small grains and causes significant losses in yield and grain quality. In our environmental conditions, dominant species is Fusarium graminearum Group 2. During 2009/10 there was a significant Fusarium infestation on wheat, barley and triticale. The aim of this study was to examine the contents of deoxynivalenol (DON) in cereal samples taken after 2009/10 harvest season. We analyzed 22 NS varieties of small grains from Rimski Sancevi, including 16 varieties of winter wheat, one facultative wheat variety, four varieties of winter barley and one variety of triticale. Analytical methods based on clean-up by solid-phase extraction (SPE) columns and detection by liquid chromatography were used. Fifteen out the 22 analyzed samples were positive for the presence of DON at a mean level of 0.537 mg/kg. The highest concentration was 1.952 mg/kg. These findings were in correlation with percentage of the Fusarium damaged kernels.

Incidence of deoxynivalenol in Serbian wheat and barley.

One hundred thirty-nine small-grain cereal (wheat and barley) samples collected during the 2010 harvest in Serbia were tested for deoxynivalenol (DON) contamination. Samples were classified into four different groups and then analyzed by analytical methods based on cleanup by solid-phase extraction and detection by liquid chromatography after the validation. Limits of detection of DON were 18 and 22 μg/kg for wheat and barley, respectively, and limits of quantification were 60 and 73 μg/kg for wheat and barley, respectively. Obtained recovery values for wheat and barley samples ranged from 93.7 to 105.8% and from 84.7 to 89.2%, respectively. Analysis of 128 wheat samples showed that 100 (78.1%) of them were contaminated with DON at the levels ranging from 64 to 4,808 μg/kg. The contamination level of even 16 (12.5%) samples was above the established maximum tolerable limits adopted by the European Commission (EC) and Serbian regulation. In the 11 examined barley samples, DON was found in 3 (27.3%), with the levels ranging from 118 to 355 μg/kg, although none of the samples were contaminated above the limit for this cereal. The results obtained were analyzed as a function of climatic conditions and compared with the previous data on the presence of DON in Serbia.

Mycobiota on common wheat ( Triticum aestivum) and spelt (Triticum aestivum ssp. spelta) grains from the region of Vojvodina in 2015

The incidence of mycobiota on common wheat (Triticum aestivum) and spelt (Triticum aestivum ssp. spelta) samples, collected during the harvest in 2015, was investigated. The obtained results showed that more genera of mycobiota were isolated from the common wheat grains than from the spelt grains. The most frequently isolated species from common wheat grains belonged to genus Alternaria (41.7%), followed by Fusarium (15.2%), while the incidence of this mycobiota on the spelt grains were 32.4% and 10.4%, respectively. Aspergillus flavus was identified in 40.0% wheat samples, with the incidence of 2.0%. Additionally, this study was undertaken in respect of the occurrence and toxigenic potential of A. flavus isolates from these small grain cereals. A simple screening method was applied to determine toxigenic profiles (aflatoxins production) of A. flavus isolates from common wheat. The results revealed the importance of precise investigation of mycobiota distribution on common wheat and spelt grains, and especially the investigation of toxigenic potential of A. flavus.

Preliminary Results on Deoxynivalenol Degradation in Maize by UVA and UVC Irradiation

Summary The aim of this work was to investigate the possibility of using UV irradiation for degradation of deoxynivalenol (DON) in naturally contaminated maize samples. The study was carried out by varying the distance of the contaminated maize from the UVA (368 nm) and UVC (254 nm) light source and duration of exposure of contaminated maize to UV irradiation. Two control samples of maize were used for the irradiation procedure, at DON levels of 1.902 mg/kg and 5.334 mg/kg. The samples were exposed to both UVA and UVC light at two different distances from UV lamp (15 and 30 cm) during three exposure intervals (30, 60 and 120 minutes). After irradiation DON content was determinated so the reduction levels could be quantified. Generally, the results showed reduced DON content in treated samples, but they were not consistent. The most probable reason for this was a very uneven DON distribution in naturally contaminated samples. For this reason, further research must be performed and should include irradiation of artificially inoculated samples with consistent DON distribution, the amount of irradiated sample needs to be enlarged and the higher number of replicates should be analyzed. As an additional improvement, an increase in frequency of sample mixing during the irradiation procedure needs to be done.