Marko M. Jauković

Aflatoxins are the most widespread mycotoxins primarиly produced by fungi of the genus Aspergillus such as A. flavus and A. parasiticus, infecting grains during storage, spices, nuts, milk and animal feed. Even in low concentrations, they are highly toxic. Major forms of aflatoxins include B1, B2, G1, G2, and M1. Mammals that ingest AFB1 contaminated food eliminate amounts of the main hepatic metabolite known as milk toxin or aflatoxin M1 (AFM1) via milk. The incidence of contamination of aflatoxin in maize, feed mixtures, milk and cheese samples collected from Serbian producers was investigated by using the competitive enzyme linked immunosorbent assay (ELISA) technique. In this study, a total of 22 samples of maize, 25 samples of feed mixtures, 284 samples of raw, pasteurised and UHT milk and 20 samples of cheese were examined in 2021. Aflatoxin B1 (AFB1) was quantified in 3 samples (13.6%) of maize, at levels ranging from 2.45μg/kg to 48.31μg/kg and 12 samples (48%) of feed mixtures at levels ranging from 2.04 μg/kg to 21.48 μg/kg. On the other hand, AFM1 was quantified in 51 samples (17.90%) of milk at levels ranging 0.02 μg/kg to 0.26 μg/kg and 15 samples (75%) of cheese at levels ranging from 0.15 μg/kg to 0.46 μg/kg. In the Republic of Serbia, maximum limit of AFB1 in maize used for livestock is 30 μg/kg and for feed mixtures for dairy cows is 5 μg/kg. On the other hand, maximum limit of AFM1 in milk is 0.25 μg/kg. Maximum limit of AFM1 in cheese is not set. These results suggest the obvious presence of AFB1 in maize and the fact that number of feed mixture, milk and cheese samples contaminated with aflatoxins is not negligible. The occurence of aflatoxins in raw milk and comercially available milk is one of the most serious problems, as milk is a key source of nutrients for infants and young children. There­fore, continuous monitoring over milk is necessary as well as further research and risk analysis on AFM1 presence in cheese.

In Serbia, aspergillus ear rot caused by the disease pathogen Aspergillus parasiticus (A. parasiticus) was first detected in 2012 under both field and storage conditions. Global climate shifts, primarily warming, favour the contamination of maize with aflatoxins in temperate climates, including Serbia. A five-year study (2012–2016) comprising of 46 A. parasiticus strains isolated from maize kernels was performed to observe the morphological, molecular, pathogenic, and toxigenic traits of this pathogen. The HPLC method was applied to evaluate mycotoxin concentrations in this causal agent. The A. parasiticus isolates synthesised mainly aflatoxin AFB1 (84.78%). The percentage of isolates synthesising aflatoxin AFG1 (15.22%) was considerably lower. Furthermore, the concentration of AFG1 was higher than that of AFB1 in eight isolates. The polyphase approach, used to characterise isolates, showed that they were A. parasiticus species. This identification was verified by the multiplex RLFP-PCR detection method with the use of restriction enzymes. These results form an excellent baseline for further studies with the aim of application in the production, processing, and storage of cereal grains and seeds, and in technological processes to ensure the safe production of food and feed.

The primary aim of this research was to investigate the effect of dilute alkaline steeping on molds and toxicity of maize malt. Samples of maize were collected from one farm located in the Serbian autonomous region Vojvodina. Steeping regimes were performed by using 0.1, 0.2, and 0.3% NaOH solutions. The effects of these solutions on mold contamination, total aflatoxin (AFLA), deoxynivalenol (DON), zearalenone (ZON), rootlet length, moisture, total nitrogen, content of protein, fat content, ash content, content of total carbohydrates, and energy value of maize malt were evaluated. Steeping in 0.1, 0.2, and 0.3% NaOH reduced the levels of molds from 10⁶ to 10⁴ CFU/g, and steeping in 0.3% NaOH eliminated some of the mold genera. Also, it significantly reduced (P < 0.05) the level of total AFLA, DON, and ZON. However, steeping in (control) water also significantly reduced (P < 0.05) the level of DON and ZON. Malting also significantly reduced (P < 0.05) total nitrogen and therefore content of proteins. However, steeping in 0.1, 0.2, and 0.3% NaOH caused significantly smaller reductions (P < 0.05). Significant reduction (P < 0.05) was also observed in the rootlet length, content of fat, and ash content. Steeping in 0.3% NaOH is proposed as a method for the reduction of mold and AFLA, DON, and ZON contamination during maize malting. Energy value of maize increases in the malting process regardless of the steeping regime.