Determination of the polyphenolic content and the antioxidant activities of four indigenous Greek red and white wine varieties

Greece has a long history in viticulture and vinification, cultivating indigenous and imported grape varietals for the production of fine wines. The dominant Greek red grape varieties are Xinomavro and Agiorgitiko, while the most recognizable Greek white grape varieties are Assyrtiko and Malagouzia. In the present study, the biological activities of monovarietal wines, derived from the aforementioned indigenous Greek grape varieties, were investigated by evaluating their polyphenolic content and antioxidant potency in vitro, using a well‑established panel of cell‑free assays. According to the results obtained, the red wines contained higher levels of polyphenolic compounds and exhibited more prominent antioxidant activities than the white wines. Among the different wine varieties, Xinomavro was the most potent, exhibiting a high concentration of polyphenols and notable antioxidant properties, whereas Malagouzia was the least efficacious. Finally, the correlation analysis between the total polyphenolic content and antioxidant capacity of the red and white wine varieties revealed a proportional correlation in almost all cases, indicating that the antioxidant activities strongly correlated with the phenolic content. Overall, the findings of the present study suggest that the monovarietal wines of these indigenous Greek grape varieties, and particularly Xinomavro, are highly bioactive, and their moderate consumption may be associated with health‑promoting effects.