Optimization of Microwave-Assisted Extraction of Curcumin from Curcuma longa L. (Turmeric) and Evaluation of Antioxidant Activity in Multi-Test Systems

Turmeric ( Curcuma longa L.) is a medicinal plant, and its biological activities mainly arise from the main constituent, known as diferuloylmethane or curcumin. In the present paper, microwave-assisted extraction (MAE) was investigated for the recovery of curcumin from turmeric in comparison to conventional heat-assisted extraction (CHAE) technique. Various experimental conditions, such as solvent concentration (0-100%, v/v), MAE temperature (30-130 oC) and MAE time (0-20 min) were investigated to optimize the extraction of curcumin from turmeric. The identification and quantification of curcumin in extracts were performed by HPLC-DAD system. Antioxidant potential and radical scavenging abilities of microwave-assisted extract and conventional heat-assisted extract of turmeric (MAET and CHAET) were evaluated using different systems including total phenolic content (TPC), total antioxidant capacity (TAC), and radical scavenging activities. MAET and CHAET showed high antioxidant activity in all test systems, but the antioxidant properties of MAET were stronger than those of CHAET.