Abstract:

Objective: To establish optimal conditions for the microwave-assisted extraction of ploysaccharide from
Hovenia acerba Lindl by means of mathematical modeling and to explore the hydroxyl radical scavenging activity of the
polysaccharide extract from Hovenia acerba Lindl. Methods: Box-Behnken design was used to develop a regression model
indicating the effect of three key process parameters including microwave power, solvent-to-solid ratio and extractiom time
on the extraction efficiency of polysaccharide. Based on the model, these extraction prameters were optimized by response
surface analysis. The antioxidant activity in vitro of the polysaccharide obtained was evaluated based on the reaction
between hydroxyl radical and salicylic acid. Results: The optimal extraction conditions were obtained as follows: 504.3 W,
25:1 and 21.9 min for microwave power, solvent-to-solid ratio and extraction time, respectively. The extraction efficiency
of polysaccharide under these conditions was 10.84%. The resulting polysaccharide had strong hydroxyl radical scavenging
activity with an IC50 of 205.87 μg/mL.

Key words: Hovenia acerba Lind, polysaccharide, microwave-assisted extraction, response surface methodology, free radical scavenging activity