Study On Degradation Of Deoxynivalenol And Zearalenone In Wheat By Electrochemical Methods

Deoxynivalenol（DON）and zearalenone（ZEN）are secondary metabolites produced by Fusarium spp.,which cause several adverse effects including reproductive toxicity,immune toxicity,and cytotoxicity,mainly co-contaminating wheat,corn,and other cereals.Developing efficient and safe degradation methods is crucial for food safety and human health.Compared with traditional degradation methods such as adsorption,oxidation,and enzyme,electrochemical methods（electrochemical oxidation and electrochemical reduction）have advantages of high efficiency,no secondary pollution and environmental friendliness.In this study,the degradation of DON and ZEN and their co-occurrence were studied by electrochemical oxidation and electrochemical reduction.After degradation,the structure of degradation products was identified through mass spectrometry（MS）,and their toxicity were evaluated by ECOSAR software and cytotoxicity assay.On this basis,the optimized method was applied to degrade DON and ZEN in wheat.The main research results are as follows:For DON,the effects of potentials,degradation time and Na Cl concentration on electrochemical oxidation and electrochemical reduction degradation rate were studied in solution.The results showed that the degradation rate of DON increased with the rise of potential,degradation time and Na Cl concentration.Electrochemical oxidation could degrade DON completely within 20 min at 1.5 V,while electrochemical reduction degraded only 49.36%±0.81%after 60 min at-9.0 V.According to MS,the structural changes of electrochemical oxidation products were mainly concentrated in the carbon-carbon double bond and epoxy ring.The simulation showed that the LC₅₀ and EC₅₀ of all electrochemical oxidation products are higher than 100 mg/L,and the Ch Vs are higher than 10 mg/L,indicating that all products are harmless.On this basis,electrochemical oxidation was applied in wheat.With the orthogonal analysis and the optimization of p H and solid-liquid ratio,finally a degradation rate of 91.07%±1.83%was obtained.After degradation,the content met the standard limit,and the product was also harmless.For ZEN,electrochemical oxidation and electrochemical reduction both degraded ZEN completely in solution within 8 min（3.0 V,0.20 mol/L Na Cl）and 20 min（-9.0 V,0.20 mol/L Na Cl）,respectively.The structural changes of electrochemical oxidation products were mainly in carbon-carbon double bonds,and that of electrochemical reduction products were mainly in carbon-carbon double bonds and ketone groups.From simulation,the electrochemical oxidation products have low acute and chronic toxicity,and the product at 9.0 V is harmless(LC₅₀/EC₅₀>100 mg/L,Ch Vs>10 mg/L).CCK-8 assay further confirmed the less cytotoxic of such compounds.However,LC₅₀,EC₅₀ and Ch Vs of all electrochemical reduction products were lower than 1 mg/L,and cell viabilities were lower than that of ZEN,meaning the higher toxicity of electrochemical reduction products.Therefore,electrochemical oxidation was applied in wheat,and a degradation rate up to 92.32%±2.37%was achieved.The content met the standard limit,and the product was harmless.For the co-occurrence of DON and ZEN,electrochemical oxidation was selected according to previous studies.In solution,DON and ZEN can be completely degraded within 8min and 12 min（3.0 V,0.20 mol/L Na Cl）,respectively.The structure changes of their electrochemical oxidation products are mainly in the carbon-carbon double bond.In terms of toxicity,CCK-8 method was used to demonstrate the cytotoxicity of mixed product.The results showed that the product at 9.0 V has no cytotoxicity.In real samples,the content of both can be reduced to the standard limit,and the degradation rate reached 80.90%±1.41%and 90.58%±3.12%,respectively.The degradation products were also harmless.In addition,the fatty acid value,protein content,color and rheological properties of wheat did not vary significantly after electrochemical oxidation at the optimum conditions.Overall,this work explored the possibility of electrochemical oxidation and electrochemical reduction degradation of mycotoxins,providing a novel idea and theoretical basis for degradation of mycotoxins,ensuring global food safety and human health.