Abstract:

The ultrasound-assisted extraction of quercetin from mulberry leaves was optimized using response surface
methodology. The yield of quercetin was investigated with response to four main variables, i.e., liquid/solid ratio, ethanol
concentration, extraction time, ultrasonic power, and extraction temperature. Three parallel experiments carried out under the
optimal extraction conditions (51% ethanol as the extraction solvent with a liquid/solid ratio of 26:1 (mL/g), ultrasonication
with an output power of 200 W, and an extraction temperature of 70 ℃) resulted in an extraction yield of 11.13 mg/g,
agreeing with the predicted value (11.31 mg/g). The proposed prediction model could accurately predict the extraction yield
of quercetin, suggesting that it is plausible to optimize the extraction conditions of quercetin from mulberry leaves using
response surface methodology.

Key words: ultrasound-assisted extraction, quercetin, mulberry leaves, response surface methodology (RSM)