Atmospheric Room Temperature Plasma Pretreatment Enhances Pulsed Electric Field Extraction of Phenolic Compounds from...

The integration of emerging non-thermal technologies for the valorization of plant bioactive compounds is gaining increasing attention in food and natural product research. In this study, Atmospheric Room Temperature Plasma (ARTP) pretreatment combined with pulsed electric field (PEF) extraction was investigated as an innovative strategy to enhance the recovery of bioactive compounds from Cannabis sativa L. (cv. Futura 75) leaves. Response Surface Methodology (RSM) was employed to identify the best conditions within the investigated range for the ARTP process based on total phenolic content (TPC), DPPH^• radical scavenging activity, and ferric reducing antioxidant power (FRAP). Under the best conditions within the investigated range (16.6 mm electrode-sample distance, 1.6 mm sample thickness, 70% plasma intensity, 10 L min^-1 nitrogen flow, and 1 min treatment), ARTP pretreatment increased TPC, FRAP, and DPPH values by 23.0%, 68.6%, and 46.1%, respectively, compared with PEF extraction alone. HPLC-DAD analysis confirmed that ARTP pretreatment selectively enhanced the recovery of the identified phenolic compounds, particularly protocatechuic acid and luteolin-7-O-glucoside, supporting the observed increases in antioxidant capacity. The extract obtained under the best conditions within the investigated range was incorporated into a model vinegar system (6% v/v acetic acid), and its stability was evaluated over 28 days by investigating the effects of extract concentration, storage temperature, and light exposure on TPC and antioxidant capacity. Elevated temperature (40 °C) and light exposure accelerated antioxidant degradation, whereas the highest extract concentration (1.2 g L^-1), storage at ambient temperature (20 °C), and absence of light resulted in improved stability. These findings demonstrate that the combined ARTP-PEF approach enhances phenolic extraction from C. sativa leaves and yields extracts with improved stability, highlighting its potential for developing functional ingredients for acidified food systems.