Dielectric barrier discharge (DBD) plasma has been utilized as a sustainable technology to enhance seed germination in various plant species. The objective of this research was to identify the mechanism of physicochemical properties and antioxidant enzyme activities to promote kangkong (Ipomoea aquatica Forssk.) seed germination using different durations of DBD plasma treatments. Seeds were exposed to atmospheric DBD plasma from 5 to 20 min, compared to non-treated seeds as the control. According to SEM images, the seed surface had cracks and grew wider as a result of the prolonged DBD plasma treatments. A longer DBD plasma treatment exhibited a lower water contact angle and increased water absorption. DBD plasma treatments strongly improved germination percentages and hydrogen peroxide (H₂O₂) contents. Seeds treated with DBD plasma for 20 min showed the highest malondialdehyde (MDA) content and the lowest field emergence. Catalase (CAT) activity increased under DBD plasma treatments for 5 and 10 min. Ascorbate peroxidase (APX) and superoxide dismutase (SOD) activities were not statistically different among the treatments. This finding suggested that DBD plasma treatments stimulated the germination of kangkong seeds by modifying the seed surface, and upregulating H₂O₂ content and CAT activity. Five minutes was an appropriate time to treat DBD plasma.

Enhancing the nutraceutical value of health-promoting foods is a strategy to mitigate non-communicable diseases (NCDs), which pose a global health threat. This study aimed to improve the growth, bioactive compound content, and antioxidant activity of kangkong (Ipomoea aquatica Forssk.) microgreens through the application of dielectric barrier discharge (DBD) plasma at different treatment durations. Seeds from two cultivars, Pugun 19 (PG) and Banhann (BH), were treated with DBD plasma for 5 to 20 min, compared to untreated seeds as the control. DBD plasma treatments had no significant effect on the dry weight of BH, whereas a 10 min treatment resulted in the highest dry weight in PG. Principal component analysis exhibited that treating PG seeds with 5 min of DBD plasma increased coumaric acid, total flavonoids, and DPPH and FRAP activities. Meanwhile, exposing BH seeds to 10 min DBD plasma treatment enhanced carotenoids content, as well as ABTS and antiglycation activities. Based on these results, the optimal time for DBD plasma treatment to improve the quality of kangkong microgreens was 5 min for PG and 10 min for BH. These findings indicate that DBD plasma treatment offers potential applications in sustainable agriculture and food biofortification.