Optimization Microwave-Assisted Extraction of Moringa oleifera Leaves Using Response Surface Methodology Focused on Extracting Phenolic And Flavonoid With Antioxidant Activity

Moringa oleifera is a plant with high levels of metabolites that possess pharmacological effect such as antioxidant. Therefore, it is crucial to study the extraction conditions of this plant to obtain the optimal amount of metabolites and pharmacological benefits. This research aimed to determine the optimal extraction time, ethanol concentration, and solid-solvent ratio for M. oleifera extraction using MAE method based on RSM to generate the highest total phenolic content (TPC), total flavonoid content (TFC), and antioxidant activities of 2,2-diphenyl-1-picrylhydrazyl (DPPH), ferric-reducing antioxidant power (FRAP), and cupric ion-reducing antioxidant capacity (CUPRAC). RSM was designed using Design Expert version 13.0. TPC and TFC were measured using the calorimetry method. Antioxidant capacities were evaluated using DPPH, FRAP, and CUPRAC method. RSM resulted in a quadratic model for all dependent variables. The highest TPC, TFC, and CUPRAC was found with extraction time (A) of 3 minutes, ethanol concentration (B) of 60%, and solid-solvent rasio (C) of 15 mL/g while the DPPH and FRAP methods were found with 1 minute, 60% ethanol, and 15 mL/g. The optimum formulation was obtained with 2.119 minutes, 57.618%, and 1:15 g/mL. The verification results showed that the optimum formulation was accurate with %RSE of <10%. RSM succeeded in optimizing the extraction conditions of M. oleifera by varying the extraction time, ethanol concentration, and solid-solvent ratio. The optimal conditions obtained for the extraction of M. oleifera can be applied to the exploration of the potential development of M. oleifera as a medicinal plant.