Evaluation of Bioactive Stability and Carbon Footprint of Clitoria ternatea L. Flower Drying by Dielectric Barrier Discharge Cold Plasma Pretreatment

The Clitoria ternatea L. ( C. ternatea L.) flower contains several bioactive substances, such as anthocyanins, flavonoids, and phenolics, which are known to offer advantages for health. However, the drying techniques affect these beneficial compounds' availability, thereby affecting the functional benefits. Thus, the purpose of this study was to assess the effects of dielectric barrier discharge cold plasma (DBD CP) pretreatment on drying performance, bioactive stability, and the carbon footprint (CF) of C. ternatea L. flower. DBD CP pretreatment was applied at 3, 5, 7, and 9 kV, followed by drying and analysis of anthocyanin, flavonoid, phenolic, and tannin content, as well as antioxidant activity using DPPH, ABTS, and FRAP analyses. The results showed that DBD CP pretreatment effectively increased the drying rate, with 9 kV demonstrating the highest drying rate (1.07% MC wb/min). Drying curve modeling was conducted to describe the kinetics of C. ternatea under different treatments. Among the evaluated models, Midilli et al. model showed the best performance in describing the drying behavior of C. ternatea , with the highest R 2 value (up to 0.99944) as well as very low RMSE (0.00750–0.01420) and X 2 (0.00009–0.00034) values, indicating excellent agreement between the experimental and predicted data. DBD CP treatment had higher bioactive content compared to the control, including anthocyanin content (20.87–52%), phenolic compounds (25.28–70.04%), and flavonoid (11.61–44.70%). Antioxidant activity also increased, as indicated by DPPH (5–13%), ABTS (35–108.11%), and FRAP (9.4–32.18%), while tannin content decreased by 19.24–41.56%. CF showed a decrease from 0.0248 kg CO₂ eq.kWh⁻¹ (control) to 0.0177–0.0219 kg CO₂ eq.kWh⁻¹ in CP-treated samples. In general, DBD CP pretreatment accelerated drying, increased drying rate, and enhanced bioactive stability and antioxidant activity. This technology shows strong potential for industrial application in food drying processes, particularly for preserving bioactive compounds while reducing DBD CP.