4.2. Sample Preparation

Wines from the four Greek flagship varieties, two from white (Asyrtiko, Malagouzia) and two from red (Xinomavro and Agiorgitiko) grapes, were selected. Vinification process included the fermentation and filtration of generated wine in inox vessels without further maturation in wooden barrels. All wine varieties tested were produced in the year 2020. A basic enological analysis of these wine varieties is presented in Table S2. To remove the contained ethanol, all wines were concentrated in a rotary evaporator (Büchi Labortechnik AG, Flawil, Switzerland) at 40 °C until their volume was reduced by half. Subsequently, an absorption resin treatment was employed using polymeric resin (Amberlite^® XAD-4, Supelco, Bellefonte, PA, USA), and the wines were consecutively recovered using analytical grade isopropanol (Fischer Scientific, Pittsburg, PA, USA). Samples were once again dried in a rotary evaporator and lyophilized for complete solvent removal, weighted, and stored in −20 °C. Finally, all 4 varieties were sampled using similar protocols simultaneously to allow us to compare their relative differences in phenol content and antioxidant efficacy.