Abstract:

The microwave-assisted extraction of polysaccharides from Cercis chinensis Bunge flowers was optimized with
the combined use of single-factor method and response surface methodology based on Box-Behnken design. A regression
surface model was developed indicating the effects of three operating parameters on extraction efficiency. The antioxidant
activity of the extracted polysaccharides was evaluated by DPPH, hydroxyl radical scavenging and Fe3+ reducing power
assays. The optimal extraction conditions were determined as a solvent to flower ratio of 40:1 (mL/g), 16 min extraction
time and 2 kW microwave power, resulting in an extraction yield of 30.81 mg/g. Antioxidant tests indicated that the
polysaccharides obtained by microwave-assisted extraction had antioxidant activity higher than that of those extracted by
boiling. Moreover, the former method gave a higher yield of polysaccharides.

Key words: Cercis chinensis Bunge, microwave-assisted extraction, polysaccharides, response surface analysis, antioxidant activity