*2.2. Chemicals*

Water, methanol, acetonitrile, and hexane were HPLC/MS grade and were provided by Sigma Aldrich (Milan, Italy), as were 6-hydroxy-2,5,7,8-tetramethylchromane-2-carboxylic acid (Trolox), 2,2-diphenyl-1-picrylhydrazyl (DPPH), quinic acid, rutin, verbascoside, quercitrin, luteolin 7 glucoside, luteolin 7 rutinoside, oleuropein, luteolin, quercetin, apigenin 7 glucoside, cyanidin 3 glucoside, and cyanidin 3 rutinoside, which were of analytical standard grade.

#### *2.3. Total Phenolic Content (TPC)*

Phenols were determined using the Folin–Ciocalteau method described by Singleton and Rossi [17]. Here, 500 μL of olive extract were mixed with 2.5 mL of distilled water and 500 μL of Folin–Ciocalteau reagent. After 4 min, 2 mL of 10% NaCO3 and 4.5 mL of distilled water were added. After one hour, the UV-VIS spectrophotometer absorbance was reported (λ = 756 nm).

A calibration curve was calculated using the gallic acid as reference. The calculated equation was:

> Optical Density (O.D.) = 4.958X + 0.0437 with *R*<sup>2</sup> = 0.9997

Results were reported as gallic acid equivalents (mg/g of dried pulp).
