Insights into the highly efficient detoxification of the biotoxin patulin in water by discharge plasma oxidation

Patulin is a neurotoxic secondary metabolite and is widely present in fruit-based products and even in drinking water. The low-temperature discharge plasma approach was developed to detoxify patulin in water. Patulin decomposition and mineralization efficiencies reached 93% and 74% at an applied voltage of 16 kV in a 30 min treatment period, respectively. 1O2, OH, O2−, and hydrated electrons generated in the discharge plasma process contributed to patulin decomposition. The lactone and hemiacetal groups that are responsible for the toxicity of patulin were significantly destroyed by discharge plasma oxidation, and some ring-opening intermediates, such as ethers, organic acids, and alcohols, were generated. Patulin decomposition pathways in this low-temperature discharge plasma process were then proposed. Model prediction indicated that acute oral toxicity in rats and developmental toxicity decreased after discharge plasma treatment, which was verified by actual cytotoxicity tests using yeast cells and HepG2 human hepatocellular carcinoma cells.