The total phenolic content of the crackers were determined
based on the Folin–Ciocalteu (FC) method [11]. In brief,
50 lL of the sample extract was mixed with 250 lL of freshly
prepared FC reagent. After incubation for 5 min at room temperature,
0.75 mL of (7.5%, w/v) sodium carbonate solution
and 3 ml distilled water were added and the solution was mixed
thoroughly and incubated for 60 min at room temperature.
Followed by this, absorbance was measured using a UV–visible
spectrophotometer (Jenway 6715) at 765 nm. A suitable
calibration curve was prepared using standard Gallic acid solution.
All the results were expressed as mg Gallic acid equivalents
(GAE) per gram of sample.