Multi-mycotoxin contamination in Serbian corn during 2021-2023

Mycotoxin contamination in corn poses significant food and feed safety risks, particularly in regions with variable climatic conditions like Serbia.

This study investigated the occurrence of regulated mycotoxins in corn harvested across the Republic of Serbia from 2021 to 2023, emphasizing the impact of climatic factors.

Using validated analytical methods, a total of 548 samples of unprocessed corn grains were analysed for the presence of key mycotoxins, including:

• Aflatoxins
• Ochratoxin A
  
• Zearalenone
• Deoxynivalenol
• Fumonisins
• Type A trichothecenes (T-2 and HT-2 toxins)

The results revealed high contamination frequencies, with aflatoxins and fumonisins being the most prevalent.

The results revealed substantial temporal variability and frequent co-contamination of mycotoxins.

AFLATOXIN CONTAMINATION

Aflatoxin B1 (AFB1) was the most concerning contaminant, with 73.2 % of the samples in 2022 exceeding the European regulatory limit for human consumption (5 μg/kg) for un processed corn grains, reaching peak concentrations of 527 μg/kg, which is 105.4 times higher than the allowed limit.

For animal feed, the limit of 20 μg/kg was exceeded in 40.5 % of the samples, with the highest concentration being 26.4 times greater than the maximum allowable level.

FUMONISIN CONTAMINATION

Fumonisins contamination was also high, particularly in 2021, with fumonisin B1 (FB1) detected in 87.1 % of samples and average concentrations reaching 4532 μg/kg.

Although levels decreased in 2023 (70.7 % occurrence, average 885 μg/kg), contamination remained significant.

DEOXYNIVALENOL CONTAMINATION

Deoxynivalenol (DON) contamination was consistently high (>70% of samples), with peak concentrations of 606 μg/kg recorded in 2021.

ZEARALENONE & OCHRATOXIN A CONTAMINATION

Zearalenone (ZEN) and ochratoxin A (OTA) occurred less frequently, but ZEN levels peaked in 2022 at 357.6 μg/kg, which is above the regulatory limit of 350 μg/kg for food.

TRICHOTHECENES CONTAMINATION

Trichothecenes (HT-2 and T-2 toxins) were detected sporadically, with concentrations well below critical thresholds.

The analysis demonstrated that temperature, humidity, and rainfall during the growing and harvest seasons strongly influenced mycotoxin levels, with the most severe contamination occurring under specific climatic conditions.

Notably, the highest mycotoxin levels, like aflatoxins, were linked to warmer temperatures and lower rainfall.

The high non-compliance rates for aflatoxins and fumonisins and co-contamination pose significant food and feed safety risks.

• From a public health perspective, chronic exposure to contaminated corn increases the likelihood of carcinogenesis and reproductive disorders.
• Reduced productivity and bioaccumulation in animal tissues/products represent serious economic and safety concerns for livestock.