Dielectric barrier discharge cold plasma inactivation of Ephestia kuehniella and quality assessment of wheat flour

This study investigated the effectiveness of cold dielectric barrier discharge (DBD) plasma for controlling different developmental stages of the Mediterranean flour moth ( Ephestia kuehniella) in wheat flour. Eggs, larvae, and pupae were treated under different voltage and exposure time combinations using a dual power supply DBD system. Each treatment was performed with five replicates. Plasma treatment showed clear stage-dependent efficacy. The optimum treatment reduced adult emergence from eggs by approximately 88%, whereas larvae were the most susceptible stage, exhibiting nearly 100% mortality at 19 kV after 5–9 min of treatment. Larval mortality continued to increase during the 10-day post-treatment period. Pupae were the most tolerant stage, with the greatest suppression of adult emergence achieved at 24 kV for 13 min. To determine whether insecticidal treatments affected the commodity, selected physicochemical properties of wheat flour were evaluated. Color measurements revealed only minor changes (ΔE = 1.05 ± 0.83). SEM observations showed slight qualitative surface modifications, while ATR-FTIR analysis indicated limited chemical changes consistent with oxidation. Overall, the results demonstrate stage-dependent insecticidal efficacy of atmospheric DBD plasma with only limited physicochemical modifications to wheat flour under the conditions evaluated.