Innovative extraction with green technologies: phenolic and antioxidant profiling of <i>Moringa oleifera</i> leaves using a ternary deep eutectic solvent and ultrasound

Abstract This study aims to investigate the individual and interactive effects of process parameters affecting the biologically active components of Moringa oleifera leaf, and to determine the optimal levels of these parameters. Ternary deep eutectic solvent combined with ultrasound‐assisted extraction was investigated. Ternary deep eutectic solvent consists of a mixture of choline chloride, glycerol and lactic acid and attracts attention with its environmentally friendly and non‐toxic properties. The effects of process parameters such as extraction time, solid mass and particle size on total phenolic content (TPC) and radical scavenging activities (DPPH and ABTS) were evaluated with Box–Behnken design and response surface methodology. The optimum extraction conditions were determined as 20.65 min extraction time, 0.2 g solid mass and 750 μm particle size. Under these conditions, TPC (39.55 mg equivalents of gallic acid/g dried plant) and antioxidant activities (87.37% inhibition of DPPH and 49.37% inhibition of ABTS) were maximized. Additionally, the produced quadratic models showed high acceptability. Principal component analysis (PCA) was also applied to show how TPC and antioxidant activity were related to certain process parameters. To conclude, this study indicates that environmentally friendly solvents and innovative extraction techniques play an important role in obtaining biologically active compounds from natural sources and reveals the contribution of PCA in this process. In conclusion, this study has significant potential to develop sustainable and innovative methods for industrial scale extraction of biologically active components from M. oleifera .