Phenolic characterization and antioxidant assessment of Vitis vinifera L. grapes produced in Alentejo

Abstract

Wine is part of the Mediterranean diet and it’s also known by its benefits in human health when consumed with moderation due to the presence of some phytonutrients. During ripening process, red wine grapes naturally develop these compounds, namely polyphenols, which evidence the organoleptic properties. In this study, varieties commonly produced in Alentejo (Syrah, Tempranillo, Touriga Nacional and Trincadeira) were selected to evaluate the evolution of the phenolic content and the evolution of antioxidant activity during vérasion. Total phenolic compounds content and total flavonoids were evaluated by UV/Vis spectroscopy. Anthocyanins content was determined by HPLC-DAD. Antioxidant activity of grape extracts was quantified using DPPH method, total reducing power3 and β-carotene/linoleic acid system.