Modeling and optimization of sustainable extraction of valuable bioactive compounds from Foeniculum vulgare by glycerol-based deep eutectic solvent and ultrasound and heat treatment

Abstract

Foeniculum vulgare is a common spice with various ethnomedicinal applications. There is a need to explore a green and efficient method for extracting bioactive compounds from it. Thus, the current study reports for the first time, ultrasound-assisted extraction (UAE) and heat-assisted extraction (HAE) using glycerol-sodium acetate (GSA) deep eutectic solvent (DES) with optimization as per response surface methodology (RSM). The responses studied included total phenolic content (TPC), total flavonoid content (TFC), anti-radical activity (ARA), and metal-chelating activity (MCA). For both UAE and HAE, the optimum temperature and solvent-to-solid ratio (SSR) found were 30 °C and 30 mL/g and the time for UAE was 25 min and for HAE 180 min with predicted TPC, TFC, ARA, and MCA for UAE 5.26 mg GAE/g DW, 18.97 mg RE/g DW, 64.47 % and 42.71 %, respectively and for HAE 4.03 mg GAE/g DW, 15.83 mg RE/g DW, 60.84 % and 45.66 %, respectively. Thus, UAE proved to be more efficient in the recovery of bioactive compounds from F. vulgare than HAE. The optimized method was statistically significant and environmentally sustainable and can be recommended for large-scale industrial applications.