Optimization of Microwave-Assisted Extraction of Bioactive Compounds from Coriolus versicolor Mushroom Using Response Surface Methodology

Response surface methodology was applied to optimize microwave-assisted extraction (MAE) of total phenolic content (TPC) and antioxidant activity from fruiting bodies of Coriolus versicolor mushroom, and to compare its efficiency with conventional reflux extraction. A central composite design was employed for the optimization of three MAE parameters including extraction time (X₁, min), ethanol concentration (X₂, %) and microwave power (X₃, W) for the highest yield of TPC and antioxidant activity measured by 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) and ferric ion reducing antioxidant power (FRAP) assays in C. versicolor extracts. The optimum conditions were predicted as 3.8 min extraction time, 40% ethanol concentration and 125 W microwave power to obtain maximum values of TPC (470 mg GAE/100 g dm) and antioxidant activity measured by DPPH (773 µM TE/g dm), ABTS (2,930 µM TE/g dm) and FRAP (1,710 µM TE/g dm) assays, which were statistically verified by comparing with the experimentally observed values. Practical Applications: In this study, microwave-assisted extraction (MAE) showed significant potential as a green extraction method for obtaining Coriolus versicolor mushroom extract rich in polyphenols with higher antioxidant activity as compared to the extracts obtained by reflux extraction. Furthermore, MAE resulted in reduced consumption of energy, time and solvent with higher extraction yield and efficiency. This work demonstrated further feasibility studies on MAE of phytochemicals including polyphenols-rich extracts at industrial scale. Moreover, successful application of response surface methodology has opened future research avenues for optimization of bioactive components from other mushrooms of medicinal importance.