Two different drying methods- freeze drying and vacuum oven drying were applied to
Ocimum basilicum leaves to determine the proximate composition and antioxidant
activities. The results were compared to fresh leaves of Ocimum basilicum. Each sample
was prepared for determination in three different solvents- methanol, ethanol, and water
have been used. The total phenolic content (TPC) and total flavonoid content (TFC) assays
showed almost the same values in the freeze-dried sample of methanol extract as it
exhibited the highest TPC and TFC values - 54.46±1.24 mg gallic acid/g, 950±17.32 mg
quercetin/g whereas the water extract showed only 26.23±0.63 mg gallic acid/g and
543.33±56.86 mg quercetin/g, respectively. On the contrary, fresh sample with water
extract displayed the lowest TPC and TFC. In addition, the percent inhibition of 1,1-
diphenyl-2-2picrylhydrazyl (DPPH) free radical-scavenging assay ranged from 6.09±
0.47% in fresh sample with water extract to 92.60±0.58% in freeze-dried sample with
methanol extract. The ferric reducing antioxidant power (FRAP) assay values ranged from
7.62±1.09 µmol FeII/g in fresh samples with water extract to 1,160.95±15.80 µmol FeII/g
in freeze-dried sample with methanol extract. Both assays showed the same trend of result
with the highest antioxidant activity observed in freeze-dried sample with methanol extract
and the lowest from fresh samples with water extract.