Reducing power (RP), an important indicator of its antioxidant activity, was evaluated by the Fe3+ to Fe2+ transformations in the presence of plant extracts. The RP
Journal of Food and Nutrition Research 977
was expressed as absorbance values at 700 nm: greater the absorbance and higher reducing activity. The solvents used resulted in different effects on the reductive ability of leaf extracts. The reducing capacities from blueberry leaf extracts in decreasing order are as follows: 50% ethanol, 95% ethanol, 70% acetone and methanol. Anwar et al. [24] stated that the highest reducing power of flaxseeds extracts was in 100% methanolic extract followed by 80% and 100% ethanolic extracts at the concentration from 300-500μg/mL, while no significant difference was found with the concentration less than 200μg/mL between 100% methanolic extract and 80% ethanolic extract. Kaneria and Chana [7] reported that the reducing power of Syzygiumcumini leaves extracted with acetone increased from 0.33 to 1.93with an rise of extract concentration from 20 to 180 (μg/mL). Variations in concentrations and species may explain the above phenomena.