2.3. Determination of total polyphenols and liquid chromatographic analysis
of olive leaf extracts
The amount of total polyphenols in olive leaf extracts was determined
using the Folin–Ciocalteau reagent according to a slightly modified procedure
(Singleton, Orthofer, & Lamuela-Raventos, 1999). Total phenolics
were calculated in mg of gallic acid equivalents (GAE)/g dried olive
leaves, by referring to slope and intercept data of the computed leastsquares
fit of a standard calibration curve with gallic acid as the reference
standard.