Ionic liquid microwave-assisted hydrodistillation extraction of Angelica sinensis essential oil and its own anti-inflammatory and antioxidant activities

In this study, ionic liquid microwave-assisted hydrodistillation (IL-MAHD) was employed to overcome the challenges of substantial emulsification and low extraction yield which occur in the extraction process of Angelica sinensis essential oil (AEO). Additionally, an online detection system was introduced into the AEO extractor to enable real-time monitoring during the extraction process. Optimal conditions were determined as follows: material-to-liquid of 1:10, ionic liquid concentration of 0.5%, microwave power of 400 W, extraction time of 4 h, condensation temperature of 20 °C, and cooling temperature of 40 °C. Under these optimized conditions, the AEO yield reached 0.7707%, marking a 1.4066-fold increase compared to microwave-assisted hydrodistillation (MAHD) and a 3.7615-fold increase compared to hydrodistillation (HD). Meanwhile, IL-MAHD exhibited the highest relative content of (Z)-ligustilide (73.424%), and the corresponding AEO displayed significant anti-inflammatory and antioxidant effects at concentrations of 7.8125, 15.625, and 31.25 µg/g. The results of extraction kinetics and online monitoring suggested that the IL-MAHD achieved the fastest extraction yield of AEO. This study provides a new perspective on exploring a potential cost-efficient technology for the industrial extraction of essential oils.