Phenolic Compounds and Antioxidant Activity in Monovarietal Red Wines from Lazio Cultivars: A Chemometric Evaluation

Background: Antioxidant activity is currently one of the most significant characteristics of red wines, mainly attributable to phenolic components, that enhance health-promoting effects. To this purpose, it is necessary to implement simple, and reliable analytical methods for evaluating such bioactive compounds in wines according to their background. Objective: This research aims to characterize the phenolic and antioxidant activity of 48 commercial monovarietal red wines produced from eight native Lazio cultivars (“Cesanese del Piglio”, “Cesanese di Olevano Romano”, “Cesanese da Castel Franco”, “Olivella del Frusinate”, “Nostrano”, “Syrah”, “Merlot”, and “Nero Buono”), according to different winemaking techniques and vintage. Methods: The characterization was carried out through the chromatographic determination of anthocyanins (HPLC-PDA), spectrophotometric assays for total phenolic content (TPC), total flavonoid content (TFC), total phenolic acid content (TPAC), and antioxidant activity (AA) through ABTS, and DPPH assays, coupled with chemometric tools (Principal Component Analysis and Cluster Analysis). Results: The quantitative determination of phenolic compounds showed significant (p > 0.05) differences according to wine cultivars. Wine belonging to ‘Syrah’, ‘Nero Buono’, ‘Cesanese del Piglio’ and ‘Cesanese di Olevano Romano’ cultivars showed the highest TPC (2.673 – 4.094; 1.963 – 3.859, 2.104 – 3.794, and 2.668 – 3.549 mg GAE/L, respectively), as well as the highest TFC and TPAC. Conclusion: In addition, wines sharing cold maceration (i.e., COR and CP samples) resulted in the highest total anthocyanidin content with a variable malvidin and cyanidin distribution percentage; as well as younger wines (2019) showed the highest TPC and anthocyanidins content. In these regards, the natural groupings among samples obtained by chemometrics reinforce the influence of cultivar origin, the wine-making process, as well as wine aging on phenolic content and compositions, thus acting as fingerprints for specific grape cultivars.