PREVALENCE OF ALTERNARIA TOXINS IN MAIZE

Abstract

One of the most important agricultural crops in Serbia is maize (Zea mays), which also represents the most important agricultural product intended for export. In addition to the quantity and quality of the produced maize, the safety aspects must be considered as well, in order to protect human and animal health. As a result of stress factors (biotic and abiotic) during maize cultivation, maize can be contaminated with a large number of different fungal secondary metabolites, i.e. with regulated and non-regulated mycotoxins. Alternaria toxins are referred as “emerging” mycotoxins due to their possible harmful effects and consequently they are of concern for public health. The most common Alternaria species which are capable to produced toxic secondary metabolites include A. alternata, A. tenuissima, A radicina, A. arborescens, A. infectoria, A. brassicae and A. brassicicola. Since Alternaria species and their toxins are widespread in both semi-arid and humid regions, they have been isolated from a wide range of food and feed, primarily, in cereals (mainly in wheat, sorghum, and barley), fruits, vegetables, oilseeds, beverages, silage, feed, and feed ingredients. Thus, the present study was undertaken with the aim to determine the presence of three different Alternaria metabolites in 400 maize samples collected from the main maize producing regions in Northern Serbia during four years (2018 – 2021). A liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was used for the detection and quantification of alternariol (AOH), alternariol monomethyl ether (AME) and tentoxin (TEN) in maize samples. In addition, the influence of weather conditions during maize growing seasons was investigated on the frequency and level of Alternaria toxins (AOH, AME, and TEN) in maize samples. As a consequence of the influence of weather conditions in investigated years, the highest percentages of contaminated maize samples by AOH, AME and TEN were 29%, 46% and 21%, respectively in the year 2021, while the lowest percentages of 10, 11 and 1%, respectively were recorded in the year 2019. Similar to the 2019 maize growing season, in the 2018 and 2020 production years, low level of contaminated maize samples by examined Alternaria toxins were observed. Based on the results of this study, as well as, on the results of our previous investigations concerning the contamination of maize from the Republic of Serbia, it could be concluded, that the weather conditions in the investigated maize growing seasons have a significant influence on the frequency and the determined concentrations of investigated Alternaria toxins in maize. Besides in small grain cereals, the obtained results indicated the need for continuous monitoring of Alternaria metabolites, in maize, as well.