Effect of cultivar and drying methods on phenolic compounds and antioxidant capacity in olive (<i>Olea europaea</i> L.) leaves

<abstract> <p>Up to 5% of the total olive weight arriving at mill is discarded as leaves. Interest in possible uses these residues growing, because they constitute a potential cheap and abundant source compounds with high antioxidant capacity (TAC) associated phenolic content (TPC) biophenols such hydroxytyrosol (HC) oleuropein (OC), which could be used nutraceuticals or natural substitutes for synthetic antioxidants. However, studies that characterize specific cultivars, interannual variability, different drying methods are lacking. This work investigates TAC, TPC, HC OC (<italic>Olea europaea</italic> L.) leaves under four (vacuum-drying, oven-drying, freeze-drying air-drying). Leaves were collected from cultivars 'Arbequina' grown organic 'Arroniz', 'Empeltre', 'Arbosana', 'Picual' conventional systems. Among fresh samples, 'Arbosana' presented highest TPC (34.0 ± 1.1 mg gallic acid equivalents/g dry (DW)) TAC (146 20 μmol Trolox DW) lowest variability (3.2%). The tested also compared effect on OC. Freeze-drying air-drying best preserved maintained greater (14–40 mg/g than (3–20 DW). Air-dried ecological exhibited TAC. Consequently, this cultivar more valorization opportunities antioxidants.</p> </abstract>