Determination of aflatoxin and zearalenon in maize-based products

Maize (Zea mays L.) and maize-based products have an important place in the global food system in terms of nutritional value and widespread consumption. However, these products pose a high risk in terms of mycotoxin formation when appropriate conditions are not provided in the production, harvesting, transportation and storage processes. In particular, environmental factors such as high temperature and humidity facilitate the development of mycooxygenic molds such as Aspergillus and Fusarium, which can lead to the formation of toxins such as aflatoxin (AFs) and zearalenone (ZEA). Mycotoxins can survive not only in field conditions, but also in processed foods due to their thermally stable structure, which directly affects the safety of products and public health. In this study, samples of maize chips (n=20), canned maize (n=15), breakfast cereal (n=15), maize with sauce (n=20) and maize flour (n=10) obtained from various markets and sales points in Çorum were analyzed by high-performance liquid chromatography (HPLC) method validated in terms of AFs and ZEA contamination. Limit of detection (LOD) values for AFB1, AFB2, AFG1, AFG2, and ZEA in maize-based samples were 0.072; 0.063; 0.075; 0.065; and 0.983 μg kg⁻¹ while limit of quantifications (LOQ) values were determined as 0.240; 0.211; 0.251; 0.218; and 3.28 μg kg⁻¹ respectively. Of the 80 maize-based products analyzed, AFs above the LOD were found in 43 (53.8%) samples. It was determined that the amount of AFs ranged between 0.648-4.60 μg kg-1 and the mean value was 1.24 μg kg-1. The presence of AFB1 was detected in all samples evaluated as AFs positive, and the AFB1 concentration in these samples was found in the range of 0.628-3.57 μg kg-1 (mean 0.967 μg kg-1). ZEA, on the other hand, was determined in 11 of 80 maize-based products (13.75%) in amounts ranging from 2.06-3.24 μg kg-1 (average 2.73 μg kg-1). While the AFB1 levels detected in 3 samples were above the ML values (2 μg kg-1) specified for cereals and cereal-based products in the EU and Turkish Food Codex Regulation, only one sample was detected at a value above the ML value (4 μg kg-1) for total AFs. The concentration of ZEA was determined to be below the ML values specified for maize-based products in the EU and TGK Regulations. In this context, it is evaluated that AFs and ZEA cannot be completely destroyed by heat processes such as frying, drying or extrusion due to their thermally stable structure, and it has been determined that processed maize products pose a higher risk of AFs contamination than ZEA contamination. For this reason, regular monitoring and risk assessment of AFs and ZEA contamination of processed maize products is of great importance in terms of public health and food safety.