2.4.1. Total phenol content
Total phenol content (TPC) in each extract was determined
using the FC method described by McDonald et al [13], with
minor modifications. The freeze-dried extract was dissolved
in distilled water to a concentration of 50 mg/mL. The calibration
curve was established using gallic acid (0e60 mg/mL).
The diluted extract or gallic acid (1.6 mL) was added to 0.2 mL
FC reagent (5-fold diluted with distilled water) and mixed
thoroughly for 3minutes. Sodium carbonate (0.2 mL, 10% w/v)
was added to the mixture and the mixture was allowed to
stand for 30 minutes at room temperature. The absorbance of
the mixture was measured at 760 nm using a UVeVIS spectrophotometer
V-550 model (Jasco, Tokyo, Japan). TPC was
expressed as milligram gallic acid equivalent per gram
defatted L. aromatica (mg GAE/g DFLA).