2.5.1. Determination of total phenolics content
The total phenolics content was determined using the Folin–
Ciocalteu reagent as followed by Abu Bakar et al. (2009). Briefly,
300 ll of extract was mixed with 2.25 ml of Folin–Ciocalteu re- agent diluted (1:10) in distilled water and allowed to stand at room
temperature for 5 min; 2.25 ml of sodium carbonate (60 g/l) solution
was added to the mixture. After 90 min at room temperature,
the absorbance was measured at 725 nm using a spectrophotometer.
The total phenolic content of the extracts was calculated and
expressed as gallic acid equivalents per gram of dry weight (mg
GAE/gDW) based on the gallic acid standard curve.