Total Phenolic Compounds (TPC)
Total phenolic compound content was determined with a spectrophotometer
(UV2450, Shimadzu, Japan) utilizing the sample preparation method that
Günç Ergönül (2006) had used. Calibration curve was obtained using the
standard solutions in different concentrations prepared from cafeic acid
stock solution. 1 g of homogenized olive sample mixed with 5 mL of
methanol:water (60:40) solution and shaked for 2 min. Then, it was
centrifuged at 3500 rpm for 10 min. The supernatant was taken into a 10
mL tube filtering through a coarse filter paper. The supernatants
obtained from the extraction which was performed two timeswere combined.
and was filled with distilled water to the volumeline . Once the sample
was well mixed, 0.1 mL was taken into 50 mL volumetric flask and 5 mL of
distilled water and 0.5 mL Folin-Ciocalteu reagent were added. After 3
min, 1 mL of 36% Na2CO3 solution was
added. Then, the sample solution was made up to the volume with
distilled water. After the solution was kept in the dark for 2 h, the
absorbance were measured at 725 nm wavelength using UV/VIS
Spectrophotometer. The concentration values that correspond to the
absorbance values were determined in the calibration curve for each
sample and the results were calculated as mgCAE/100g olive considering
the dilution factor (CAE: cafeic acid equlibrium).