Effect of cold plasma-activated water generated by piezoelectric direct discharge on the quality of diced onions during storage

This study evaluated the effects of plasma-activated water (PAW) on the quality and microbial suppression of diced onions. The cold plasma device was applied to deionized water for 10, 20, and 30 min to generate plasma-activated water. Afterwards, the samples were immersed for 10 min in PAW with ultrasonic assistance at 25 °C. The dehydrated samples were stored at 5 °C for 20 days, and analyses were performed every 4 days. The microstructure of onion samples was observed using scanning electron microscopy (SEM). The results indicated that the PAW10 effectively preserved the quality of diced onions by maintaining their weight, firmness, and antioxidant capacities, slowing down color change, suppressing respiration, and microbial growth. In contrast, no significant differences in total soluble solids and titratable acidity were observed among the treatments. The 10-minute PAW treatment in this study prolonged the shelf-life to 12 days compared to 8 days for control. Based on the findings of this study, future research should focus on optimizing PAW treatment conditins to effectively and efficiently preserve the quality and appearance of diced onions.Overall, the plasma-activated water generated by cold plasma technology may be an alternate, convenient, and successful approach for preserving fresh produce. • Plasma-activated water (PAW) treatment preserved diced onion quality during storage. • PAW influenced changes in the microstructure and ROS levels of diced onion. • PAW treatment can be an effective approach for preserving fresh-cut produces. • Optimization is required since prolonged PAW exposure can impair product quality.