Chemometric study for the performances of deep eutectic solvents during the recovery of high‐added‐value substances from Moringa oleifera leaves: Principal component analysis

Abstract

IntroductionMoringa oleifera is a plant with high antioxidant content in its leaves, flowers and seeds. It attracts the attention of researchers with the effect of its nutritional and medical advantages.ObjectiveThe purpose of the current study is to propose a deep eutectic solvent (DES)‐based ultrasound‐assisted extraction of bioactive substances from M. oleifera leaves by the application of a chemometric study.MethodologyA total of 18 different choline chloride‐based DESs were prepared by using several hydrogen bond donors (glucose, sucrose, glycerol, ethylene glycol, urea and dimethyl urea) with various molar ratios (1:1, 1:2 and 2:1) by addition of diluents (water and 50% methanol) or alone. In order to decide the best DES combination, principal component analysis (PCA) was applied. The response surface method (RSM) was used as statistical experimental design approach through the Box–Behnken design.ResultsThe best phenolic (TPC), flavonoid (TFC) and antioxidant activity yields of M. oleifera leaf extract were found to be 19.102 mg‐GAE, 10.47 mg‐CE and 24.404 mg‐TEAC per gram dried leaf under the optimal conditions (50% water content, 20% amplitude, 15 min time). The model fitting has been also found reliable depending on the statistical indicators such as p‐value (<0.0001), coefficients of determination (R2 = 0.9827, 0.9916 and 0.9864) and root mean square error (RMSE = 1.0562, 2.4656 and 0.7713).ConclusionsA chemometric study through PCA was carried out to determine the similarities and differences between the solvent groups, and the ethylene glycol‐based DES (1:2, molar ratio) with the addition of water showed the best performance.