Optimization of Ultrasound-Assisted Extraction of Polyphenols from Myrtus communis L. Pericarp

Abstract

Response surface methodology (RSM) was used to optimize the extraction of phenolics from pericap of Myrtus communis using ultrasound-assisted extraction (UAE). The results were compared with those obtained by microwave-assisted extraction (MAE) and conventional solvent extraction (CSE) methods. The individual compounds of the optimized extract obtained by UAE were identified by ultra-high-performance liquid chromatography coupled with diode array detection and electrospray ionization mass spectrometry (UHPLC-DAD-ESI-MSn). The yield of total phenolic compounds (TPC) was affected more significantly by ethanol concentration, irradiation time, liquid solvent-to-solid ratio (p < 0.0001) and amplitude (p = 0.0421) and optimal parameters conditions set by the RSM model were 70% (v/v), 7.5 min and 30%, respectively. The experimental yield of TPC (241.66 ± 12.77 mg gallic acid equivalent/g dry weight) confirmed the predicted value (235.52 ± 9.9 mg gallic acid equivalent/g dry weight), allowing also to confirm the model validity. Under optimized conditions, UAE was more efficient than MAE and CSE in extracting antioxidants, which comprised mostly myricetin glycosides. Globally, the present work demonstrated that, compared to MAE and CSE, UAE is an efficient method for phenolic extraction from M. communis pericarp, enabling to reduce the working time and the solvent consumption.

Antioxidant Activity of Polyphenolic Plant Extracts

“…The results demonstrated that ethanol concentration, irradiation time, liquid solvent-to-solid ratio and amplitude affected significantly the yield of total polyphenolic content [41]. The optimal conditions for the isolation of M. communis polyphenolic extract using UAE were 70% v/v ethanol concentration, 7.5 min irradiation time and 30% liquid solvent-to-solid ratio [41]. In addition, isolation of M. communis polyphenolic extract using UAE was more efficient than MAE and conventional solvent extraction methods [41].…”

“…The main polyphenols found in the extract were rutin, epigallocatechin, ferulic acid, and quercetin [40]. Bouaoudia-Madi et al [41] have also used UAE to isolate polyphenolic extracts from Myrtus communis L. pericarp, a plant native of the Mediterranean basin. The results demonstrated that ethanol concentration, irradiation time, liquid solvent-to-solid ratio and amplitude affected significantly the yield of total polyphenolic content [41].…”

“…Bouaoudia-Madi et al [41] have also used UAE to isolate polyphenolic extracts from Myrtus communis L. pericarp, a plant native of the Mediterranean basin. The results demonstrated that ethanol concentration, irradiation time, liquid solvent-to-solid ratio and amplitude affected significantly the yield of total polyphenolic content [41]. The optimal conditions for the isolation of M. communis polyphenolic extract using UAE were 70% v/v ethanol concentration, 7.5 min irradiation time and 30% liquid solvent-to-solid ratio [41].…”

“…The optimal conditions for the isolation of M. communis polyphenolic extract using UAE were 70% v/v ethanol concentration, 7.5 min irradiation time and 30% liquid solvent-to-solid ratio [41]. In addition, isolation of M. communis polyphenolic extract using UAE was more efficient than MAE and conventional solvent extraction methods [41]. In another study, Quiroz et al [42] used MAE to isolate polyphenolic extract from annatto (Bixa orellana L.) seeds.…”

Scrophularia Tenuipes Coss and Durieu: Phytochemical Composition and Biological Activities

“…This analysis was performed in an Ultimate 3000 (Dionex Co., San Jose, CA, USA) apparatus equipped with an ultimate 3000 Diode Array Detector (Dionex Co., San Jose, CA, USA) and coupled to a mass spectrometer, following the general procedure previously described [50]. Samples (5 mg/mL) were prepared in ethanol and analyzed through the injection of 2 µL.…”