Ultrasound versus microwave as green processes for extraction of rosmarinic, carnosic and ursolic acids from rosemary.

Ultrasound and microwave as green processes are investigated in this study, focusing on the extraction selectivity towards antioxidant extraction from rosemary leaves. Due to its richness in valuable compounds such as rosmarinic, carnosic and ursolic acids, rosemary is a reference matrix for extraction study. In this work, six alternative processes are compared: ultrasound (bath, reactor and probe), microwave (reflux under microwave, microwave under nitrogen pressure and microwave under vapor pressure). The main result of this study is that selective extraction can be achieved according to extraction techniques and therefore to the extraction process.