Decoding Cretan Wines: Phenolic Profiling of Greek Indigenous Wine Varieties Using LC-QTOF-MS

Crete's rich heritage of indigenous wine grapes remains underexplored in terms of chemical composition, with many cultivars yet to be fully characterized. This study presents a comprehensive analysis of the phenolic profile of 67 monovarietal Cretan wines produced by 10 wineries (42 white, 25 red) from 12 varieties-eight white (Assyrtiko, Dafni, Malvazia, Melissaki, Moschato Spinas, Plito, Vidiano, and Vilana) and four red (Kotsifali, Liatiko, Mandilaria, and Romeiko). A targeted LC-QTOF-MS workflow covering 45 phenolic compounds (flavonoids and non-flavonoids) was applied. Varietal differences were assessed using heteroscedasticity-robust univariate statistics (Welch's ANOVA with Games-Howell post hoc comparisons and effect-size estimation) and explored by multivariate analyses (PCA and HCA); cross-validated PLS-DA was used for descriptive classification, and MFA integrated the targeted phenolic matrix with classical indices (e.g., total phenolics, tannins, and color metrics). Red wines exhibited stronger variety-linked phenolic structuring than white wines, whereas white-wine differentiation was driven by a limited subset of marker phenolics. Given the central role of phenolic composition in overall wine quality, this study provides the first detailed phenolic characterization of 12 key indigenous Cretan grape varieties.