2.8. Total phenolics content (TP) from carrot juice and yoghurt
2.8.1. From carrot juice
The TP content was determined by the Folin-Ciocalteu method
after extraction from carrot juice with 30 mL of solvent (80%
aqueous ethanol, containing 1% conc. HCl) in a conical flask,
agitating in an orbital shaker (200 rpm, at 50 C, for 2 h), filtering
(Whatman No. 4) as described in Lima et al. (2005). The filtered
extract was used for the determination of TP content and ferric
reducing power.
The extract (100 mL) was mixed with 750 mL of Folin-Ciocalteu
reagent, allowed to stand at room temperature for 5 min and
mixed gently with 750 mL of 6% (w/v) sodium carbonate. A blank
was made by mixing distilled water and reagents. After allowing t
stand at room temperature (40 min), absorbance was measured at
725 nm using a UV/Visible spectrophotometer (model 6505 UV/Vis
Spectrophotometer, Genway UK) and the result was expressed as
milligrams of gallic acid equivalents (GAE) per kg of juice.