The olives were Moroccan Picholine variety produced during the first half of the 2019/2020 crop season from the commune of Bni Abdellah, province of Al Hoceima (Morocco). The methodologies followed in this study require a control oil, and for this aim, a commercial extra virgin olive oil from the same variety extracted by a traditional oil mill with a hydraulic press has been used. Solvents used were hexane (HEX), methyl-tertbutyl ether (MTBE), isopropyl alcohol (ISOP), methanol (MeOH), and chloroform (CLF), which were supplied by Macron (Avantor Performance Material, Center Valley, PA, USA). Reagents used for determinations as phenolphthalein, Folin–Ciocalteu reagent and sodium carbonate (Panreac, Barcelona, Spain), boron trifluoride methanol complex solution (BF3) 14% in methanol from Sigma-Aldrich (St. Louis, MO, USA), and hydroxytyrosol (HT) standard ≥ 98% were supplied by Seprox Biotech (Madrid, Spain).
The reagents used in chromatographic analyses were pure standards of oleic acid ≥ 99%, monolein ≥ 90.9%, and 1,3 diolein ≥ 99%. Squalene ≥ 98% and α-tocopherol ≥ 98% were supplied by Sigma-Aldrich (St. Louis, MO, USA), and sterol ≥ 99% were supplied by Vita-Solar Biotechnology Co., Ltd. (Xi’an, China).
The reagents used in chromatographic analyses were pure standards of oleic acid ≥ 99%, monolein ≥ 90.9%, and 1,3 diolein ≥ 99%. Squalene ≥ 98% and α-tocopherol ≥ 98% were supplied by Sigma-Aldrich (St. Louis, MO, USA), and sterol ≥ 99% were supplied by Vita-Solar Biotechnology Co., Ltd. (Xi’an, China).