Optimized Ultrasonic-assisted Extraction of Flavonoids from Osmanthus fragrans Lour. Residues

摘要

The extraction of flavonoids from Osmanthus fragrans residues was optimized using ultrasonic device. The reaction parameters studied were the ethanol concentration (60-100%), the extraction time (1.5-2.5 h) and temperature (70-90℃) using response surface methodology based on Box-Behnken design. A mathematical model was developed to show the effects of each variable and their combinatorial interactions on extraction yield of flavonoids. A high coefficient of determination (R~2 = 99.57%) indicated good agreement between the experimental and predicted values of extraction yield. The optimal values of the variables were as the followings: ethanol concentration, 82%; extraction time, 2.1 h; and temperature 82℃. The ultrasound-assisted extractions supported higher extraction yields as compared to traditional extraction and could be recommended as an alternative method for extraction of flavonoids compounds from O. fragrans residue.