Optimization of ultrasound-assisted extraction technology of polyphenols from broad bean by response surface methodology

The aim of this work was to optimize the ultrasound-assisted extraction technology of polyphenols from broad bean. On the basis of single-factor test, the response surface experiments with four factors and three levels was further utilized to investigate the effects of processing parameters, including ethanol content, solvent/material ratio, extraction time and pH on the yield of polyphenols. Results showed that the optimal extraction parameters were as follows:ethanol content 45%, solvent/material ratio 1:25 (g/mL), extraction time 20 min, and pH5.Under the optimized condition, the yield of polyphenols was up to (2.03±0.16) mg/g d.w., which was consistent with the predicted value of (2.06±0.23) mg/g d.w.. Therefore, the optimized extraction method was considered to be reliable.