Changes in Fusarium and Aspergillus Mycotoxin Content and Fatty Acid Composition after the Application of Ozone in Different Maize Hybrids.

Mycotoxins in maize represent a great threat to human health. For this reason, novel technics such as ozone treatment are used to reduce the content of maize mycotoxins. However, there is little knowledge about the effect of ozone treatment on maize quality parameters. This study investigated the changes in Fusarium and Aspergillus mycotoxins and the changes in fatty acids during the ozone treatment of maize samples. Sixteen maize hybrids were visually tested for the naturally occurring ear rot severity and treated with three different concentrations of ozone (40, 70, and 85 mg/L). Mycotoxin content in maize samples was determined using a high-performance liquid chromatography (HPLC) system, whereas dominant fatty acids were determined using gas chromatography coupled with a flame ionization detector (GC-FID). Ozone treatments could be successfully applied to reduce the content of mycotoxins in maize below the detection limit. Ozone treatments increased the content of monounsaturated fatty acids (MUFAs) and decreased the content of polyunsaturated fatty acids (PUFAs), i.e., linoleic acid (36.7% in relation to the lowest applied ozone concentration), which negatively affected the nutritional value of maize.

The European Hare (Lepus europaeus) as a Biomonitor of Lead (Pb) and Cadmium (Cd) Occurrence in the Agro Biotope of Vojvodina, Serbia.

The aim of this study was to investigate the occurrence of two heavy metals, lead and cadmium, in European hare liver samples, collected in agro biotope of northern Serbian province Vojvodina. Heavy metals such as lead (Pb) and cadmium (Cd) do not have any biological function in the animal body; however, they can be found due to the pollution in the environment. For the purpose of this study, in 196 samples from 17 different locations hare livers were analyzed for the occurrence of lead and cadmium. All samples were taken from hares harvested during the regular hunting season. The average value for lead in all analyzed samples was 884 µg/kg fresh weight (fw), with the range 59-3700 µg/kg fw. Only samples from two locations had the average concentration of lead which was within the permitted limit by the Serbian regulation. The average cadmium level in all samples was 243 µg/kg fw. The range of all samples was from 0 to 1414 µg/kg fw. Our research indicates that out of two investigated heavy metals, the occurrence of lead is more common and at a higher concentration in the agricultural development region of Vojvodina.

Fluorescence spectroscopy and multispectral imaging for fingerprinting of aflatoxin-B1 contaminated (Zea mays L.) seeds: a preliminary study.

Cereal seeds safety may be compromised by the presence of toxic contaminants, such as aflatoxins. Besides being carcinogenic, they have other adverse health effects on humans and animals. In this preliminary study, we used two non-invasive optical techniques, optical fiber fluorescence spectroscopy and multispectral imaging (MSI), for discrimination of maize seeds naturally contaminated with aflatoxin B1 (AFB1) from the uncontaminated seeds. The AFB1-contaminated seeds exhibited a red shift of the emission maximum position compared to the control samples. Using linear discrimination analysis to analyse fluorescence data, classification accuracy of 100% was obtained to discriminate uncontaminated and AFB1-contaminated seeds. The MSI analysis combined with a normalized canonical discriminant analysis, provided spectral and spatial patterns of the analysed seeds. The AFB1-contaminated seeds showed a 7.9 to 9.6-fold increase in the seed reflectance in the VIS region, and 10.4 and 12.2-fold increase in the NIR spectral region, compared with the uncontaminated seeds. Thus the MSI method classified successfully contaminated from uncontaminated seeds with high accuracy. The results may have an impact on development of spectroscopic non-invasive methods for detection of AFs presence in seeds, providing valuable information for the assessment of seed adulteration in the field of food forensics and food safety.

Biological Control of Aflatoxin in Maize Grown in Serbia.

Aspergillus flavus is the main producer of aflatoxin B1, one of the most toxic contaminants of food and feed. With global warming, climate conditions have become favourable for aflatoxin contamination of agricultural products in several European countries, including Serbia. The infection of maize with A. flavus, and aflatoxin synthesis can be controlled and reduced by application of a biocontrol product based on non-toxigenic strains of A. flavus. Biological control relies on competition between atoxigenic and toxigenic strains. This is the most commonly used biological control mechanism of aflatoxin contamination in maize in countries where aflatoxins pose a significant threat. Mytoolbox Af01, a native atoxigenic A. flavus strain, was obtained from maize grown in Serbia and used to produce a biocontrol product that was applied in irrigated and non-irrigated Serbian fields during 2016 and 2017. The application of this biocontrol product reduced aflatoxin levels in maize kernels (51-83%). The biocontrol treatment had a highly significant effect of reducing total aflatoxin contamination by 73%. This study showed that aflatoxin contamination control in Serbian maize can be achieved through biological control methods using atoxigenic A. flavus strains.

Variations in polyamine conjugates in maize (Zea mays L.) seeds contaminated with aflatoxin B1: a dose-response relationship.

BACKGROUND: Cereal seeds, such as maize seeds, are frequently contaminated with aflatoxin B1 (AFB1), one of the most dangerous naturally occurring carcinogens. In plants, phenolamides are involved in biotic stress response. The data on variations of phenolamides in AFB1-containing seeds are limited. RESULTS: Five polyamine conjugates, including two spermidine and three putrescine conjugates, were tentatively identified in methanolic extracts, using HPLC-DAD-MS. The ratio of putrescine to spermidine conjugates changed with increasing AFB1 concentration in a logistic dose-response manner, with a ratio of below 1 up to a concentration of 51.51 µg kg-1 , and approximately 2.54 and 3 at higher concentrations of 177.4 and 308.13 µg kg-1 , respectively. The observed variations of the total antioxidant activity and the total phenolic content may support this biphasic behaviour of the seeds against AFB1 stress. CONCLUSIONS: The obtained data are a contribution to the understanding of the roles of polyamine conjugates in seed defence to increasing AFB1 concentrations. According to our knowledge, this study reports for the first time the biphasic response of maize seeds to increasing AFB1 contamination level, comprising the induction of polyamine conjugate accumulation and variation in the ratio of conjugates. This dose-response relationship may provide useful information in the field of agricultural and food chemistry as an indicator of AFB1 contamination level and, hence, for selecting an appropriate seed quality. © 2020 Society of Chemical Industry.

Influence of Farm Management for Calves on Growth Performance and Meat Quality Traits Duration Fattening of Simmental Bulls and Heifers.

This study assessed the effects of farm management during rearing practices in the first months of a calf's life on growth performance and meat quality traits during the fattening period. A total of 48 Simmental calves were divided into two groups at a commercial cattle feedlot. In the first group were calves from the same farm and herd (n = 12 male and n = 12 female). The second group included calves from several different herds and farms (n = 12 male and n= 12 female). Calves were transferred to a feedlot and fed with a commercial feedlot ration at three to four months of age. The aim was to determine if identical fattening conditions at feedlot can reduce initial calf rearing differences between cattle during the fattening period. Bulls grew faster than heifers reaching higher total gain and showed significantly higher slaughter weight than heifers. Meat samples of heifers from the same herd had the highest intramuscular fat content and reddest color with significant differences among cattle groups. The most abundant fatty acid was oleic acid (C18:1), followed by palmitic (C16:0), stearic (C18:0), linoleic (C18:2), and myristic acid (C14:0). Meat samples of heifers from different herds were darkest with highest content of iron (Fe) with significant differences among cattle groups.

Emerging Fusarium Mycotoxins Fusaproliferin, Beauvericin, Enniatins, and Moniliformin in Serbian Maize.

Emerging mycotoxins such as moniliformin (MON), enniatins (ENs), beauvericin (BEA), and fusaproliferin (FUS) may contaminate maize and negatively influence the yield and quality of grain. The aim of this study was to determine the content of emerging Fusarium mycotoxins in Serbian maize from the 2016, 2017, and 2018 harvests. A total of 190 samples from commercial maize production operations in Serbia were analyzed for the presence of MON, ENs, BEA, and FUS using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The obtained results were interpreted together with weather data from each year. MON, BEA, and FUS were major contaminants, while other emerging mycotoxins were not detected or were found in fewer samples (<20%). Overall contamination was highest in 2016 when MON and BEA were found in 50-80% of samples. In 2017 and 2018, high levels of MON, FUS, and BEA were detected in regions with high precipitation and warm weather during the silking phase of maize (July and the beginning of August), when the plants are most susceptible to Fusarium infections. Since environmental conditions in Serbia are favorable for the occurrence of mycotoxigenic fungi, monitoring Fusarium toxins is essential for the production of safe food and feed.

Aflatoxins contamination of maize in Serbia: the impact of weather conditions in 2015.

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 Backa, 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 Backa. 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.

Comparison of ELISA, HPLC-FLD and HPLC-MS/MS Methods for Determination of Aflatoxin M1 in Natural Contaminated Milk Samples.

Presence of aflatoxin M1 (AFM1) in milk should be continuously controlled in order to protect the population from risks associated with its proven toxicity and carcinogenicity. During recent years, there has been an increase in demand for development of sensitive, accurate, simple and fast method which is reliable for detection of AFM1 at low concentrations found in milk samples. For that purpose, enzyme linked immunosorbent asssay (ELISA), high performance liquid chromatography with fluorescence detector (HPLC-FLD) and high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) were optimized and validated in order to apply them for AFM1 analysis in naturally contaminated milk samples, and to assess the closeness of agreement between results of three different methods. The obtained validation parameters indicate that all three methods are suitable for determination of AFM1 in milk samples. The statistical analysis of variance between the methods and the obtained correlation coefficients indicate that there is a strong correlation between methods. All three methods are satisfactory in meeting the requirements for official control purposes. To the best of author's knowledge, this study represents the first report of an investigation and comparison of ELISA, HPLC-FLD and HPLC-MS/MS methods for determination of AFM1 in naturally contaminated milk samples.

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.