Role of glycerol-based deep eutectic solvents for extraction of phytochemicals from Cichorium intybus seeds: Optimization by response surface methodology

Abstract

In this study, glycerol-based deep eutectic solvent system was employed for optimized extraction of valuable phytochemicals from the Cichorium intybus plant. Microwave assisted-glycerol based deep eutectic solvent extraction technique (MAE-GDES) was optimized with response surface methodology (RSM) with glycerol/sodium acetate DES as extracting solvent. The responses include total tannin content (TTC), total phenolic content (TPC), total flavonoid content (TFC) and DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity (DRSA). The results showed well fitted models as linear model for TPC and quadratic model for TTC, TFC and DRSA. The optimized conditions were found to be 315 W (microwave power), 2 min (extraction time), and 34 mL/g (solvents to sample ratio) with optimum TTC as 1.289 mg TAE/g dry weight (DW), TPC as 401.55 mg GAE/100 g DW, TFC as 135.64 mg RE/100 g DW and DRSA of 19.24 mg AAE/g of DW. Furthermore, the optimized MAE-GDES extract was screened for antidiabetic potential and the results showed 46.76 ± 2.03 % inhibition against α-glucosidase and 21.35 ± 0.22 % α-amylase inhibitory activity compared to standard acarbose as 43.97 ± 1.54 % and 39.46 ± 2.10 % inhibition against α-glucosidase and α-amylase enzymes, respectively at a concentration of 10 mg/mL. It is concluded by this work that glycerol/sodium-acetate based deep eutectic solvents could be used as an alternative and effective solvent for the extraction of tannins and other pharmaceutically significant phytochemicals from Chicorium intybus on a larger scale.