The FRAP reagent was initially prepared including 300 mM acetate buffer, pH 3.6, 10 mM TPTZ solution in 40 mM HCl and 20 mM FeCl3.6H2O solution. The fresh working solution was warmed at 37ºC prior using. 20 μl of gac juice were mixed with 180 μl of the FRAP solution and incubated for 4 min. The absorbance was then recorded at 593 nm using a spectrophotometer. The FRAP values were calculated by standard curves prepared with known concentrations of FeSO4 and expressed as μmol FeSO4/ml sample. Statistical analysis