Monitoring the recovery of bioactive molecules from Moringa oleifera leaves: microwave treatment vs ultrasound treatment

Abstract

There is no established standard method for obtaining valuable components from biomass materials. Therefore, each system should be considered individually, and methods should be developed specifically. In this study, two emerging technologies with pre-treatments (ultrasound and microwave) have been proposed to acquire extract from the leaves of Moringa oleifera. In order to optimize the process conditions of ultrasound-assisted extraction (UAE) and microwave-assisted extraction (MAE), response surface method (RSM) has been used with the design type of randomized Central Composite design. The yields of total phenolic (TPM) and flavonoid materials (TFM) were selected as responses. Optimum conditions were determined as 77% ethanol solution, 0.5 mm particle size, and 11% output amplitude in order to obtain maximum TPM (8.67 mg-GAE/gDP) and TFM (69.47 mg-CE/g-DP) yields in the UAE of bioactive substances from Moringa oleifera leaves. In respect of MAE system, 400 s, 200 W, 72% ethanol solution, and 0 5 mm of particle size were the optimum conditions to attain the highest TPM (18.81 mg-GAE/g-DP) and TFM (83.24 mg-CE/g-DP) yields. Moreover, two different antioxidant activity assays (DPPH and ABTS) were carried out to examine the antioxidant activity of the Moringa oleifera leaf extracts.