Optimization of Thyme Essential Oil Extraction by Microwave: An Investigation by Box–Wilson Central Composite Design (CCD)

In this study, response surface methodology based on the Box-Wilson central composite design was employed to optimize the extraction of thyme essential oil using microwave technology. Based on prior research and operational conditions, two main factors, namely steam flow rate (Q) and microwave heating power (P), were examined to assess their impact on the yield and extraction speed. A total of 12 experiments were conducted, including central cube points and axial points, with replications at the center point to ensure robustness of the results. Experimental data were analyzed using Analysis of Variance (ANOVA) to identify significant interactions and optimize extraction conditions.