The methanolic crude extracts were evaporated
to concentrate the extracts. The specific absorbance was determined
spectrophotometrically (Hitachi, Model 100–20) at
450 nm. Total carotenoid concentrations were calculated
based on β-carotene standard curve (0–300 μg mL−1;
y=0.0077x+0.0721, r2=0.9958).