Effectiveness of CAP on Emergent Alternaria Toxins in Naturally Contaminated Dried Tomatoes

In the last decade, the attention towards Alternaria toxins, belonging to the group of so-called emerging mycotoxins, has increased, as well as the adoption of non-thermal treatment to reduce their occurrence in food. This study investigated the efficacy of cold atmospheric plasma (CAP) treatment in degrading the Alternaria toxins as pure molecules and, for the first time, those naturally present in dried tomatoes. Two different CAP conditions were compared: ozone (O3) and nitrogen oxides (NOx) regimes. Five different mycotoxins produced by Alternaria alternata, such as alternariol (AOH), alternariol monomethyl ether (AME), tentoxin (TEN), altenuene (ALT), and tenuazonic acid (TeA), were selected. O3 regime was found to be very efficacious against all the mycotoxins tested (60-99% reduction), while the CAP under NOx regime exhibited variable efficacy depending on the mycotoxin molecular structure. To evaluate the CAP efficacy, twenty-five batches of dried tomatoes were analysed for the presence of Alternaria toxins. HPLC-MS/MS analyses revealed that more than 40% of the samples were contaminated by TeA, one by AOH, while other Alternaria toxins were not detected. Selected contaminated batches were subjected to CAP treatments for 15, 30 and 60 minutes in both regimes. It was observed that mycotoxin degradation increased with increasing treatment time, and the major reduction (52%) was achieved after 60 min of CAP under O3 regime. Our findings contribute to the understanding of CAP treatment as a potential method for reducing mycotoxin contamination in food products and provide insights for further optimisation and application of CAP in food safety practices.