The reducing power was determined according to the method
of Zhang etal.(2015) with minor modifications. Firstly,1.0 mL of
properly diluted sample was mixed with 1.0 mL of 1% (w/v) po-
tassium ferricyanide and incubatedat50 °C for 20 min.Following,
1.0 mL of 10% (w/v) trichloroacetic acid was added,and 2.0 mL
distilled water and 0.4 mL 0.1 %,(w/v)ferric chloride solution was
added after 10 min of incubation.The absorbance of reactive system was measured at 700nm against a blank with sample replaced by individual extraction solvent. All results were done in
triplicate, higher absorbance indicates greater reducing power.