Comparative study of conventional and pressurized liquid extraction for recovering bioactive compounds from Lippia citriodora leaves.

The extraction of bioactive compounds from Lippia citriodora leaves (Lc) has been evaluated by comparison between Pressurized Liquid Extraction (PLE) and conventional extrations combined with HPLC-ESI-TOF-MS in order to maximize recovery of phytochemicals and to know the efficiency of both methods. To achieve these goals, conventional extractions were carried out using different concentrations of ethanol and water. On the other hand, pressurized liquid extractions were performed by a Response Surface Methodology (RSM) based on a Central Composite Design 23 model to address the bioactive compounds extraction. The independent variables selected were temperature, percentage of solvent (ethanol and water) and extraction time. The response variables were extraction yield and recovery of bioactive compounds. Thus, the optimum values to maximize yield was 200 °C, 46% ethanol and 17 min. In addition, the design versatility allowed found the optimal conditions for each chemical group and to validate them. This experimental model followed by HPLC-ESI-TOF/MS analysis offer for the first time an easy, rapid, and objective manner to optimize extraction of bioactive compounds from Lc leaves by PLE, which could be used as methodology for development functional ingredients.