Evaluation of cold plasma for the control of toxigenic fungi and the mitigation of patulin.

Filamentous fungi pose a major challenge to the food industry due to spoilage and the production of mycotoxins such as patulin (PAT), which is generally resistant to conventional processing. This study evaluated the effectiveness of dielectric barrier discharge (DBD) cold plasma treatment for controlling Penicillium expansum and Paecilomyces niveus and PAT production, as well as for degrading PAT after its formation. Agar plugs from fungal colonies were exposed to cold plasma treatment at 12 kV and 5 kHz. Complete inhibition of mycelial growth was achieved after 4 min for P. expansum and 16 min for P. niveus. PAT production was significantly reduced in P. expansum, whereas no inhibition was observed for P. niveus. Cold plasma treatment promoted significant PAT degradation, with reductions of 77.15% and 85.00%, for P. expansum and P. niveus, respectively. Untargeted metabolomic and FTIR analyses revealed oxidative transformation pathways induced by cold plasma treatment, including epoxidation, hydration, and molecular fragmentation, leading to the formation of more polar and structurally modified transformation products. In silico toxicological analysis revealed that structural modifications induced by cold plasma treatment significantly reduce the acute toxicity of PAT, particularly due to the formation of simpler oxidized derivatives, although some reactive intermediates retained relevant toxicological endpoints. Overall, cold plasma treatment emerges as a promising non-thermal strategy for fungal control and PAT mitigation.