Ultrasound-assisted deep eutectic solvent extraction of flavonol glycosides from Ginkgo biloba: Optimization of efficiency and mechanism

Ultrasound-assisted extraction (UAE) is a technique that can enhance the efficiency of the extraction of bioactive ingredients. In previous work, ginkgo flavonol glycosides (GFG) were extracted using a deep eutectic solvent (DES). To further enhance mass transfer efficiency in this work, ultrasound-assisted deep eutectic solvent (UADES) was employed for GFG extraction. The optimal extraction parameters were determined to be the ultrasonic power 320 W, extraction time 63.6 min, and extraction temperature 32.5℃. The extraction yield of GFG reached 5.60 mg/g, surpassing that achieved through DES extraction. Notably, the extraction time was drastically shortened from 11.8 h to 63.6 min. The analysis of changes in micro-morphology, crystalline structure, and cellulose content of the phytoextraction solid residue revealed that the UADES effectively disrupted the crystalline regions of lignocellulose within the cell wall, and the ultrasound enhanced the solubilization of DES to lignocellulose, thus improving the efficiency of the extraction process.