Phenolic, Polysaccharide, and Color Variability in Chilean Commercial Chardonnay Wines: Influence of Closure Type, Geographic Origin, and Vintage

Chardonnay (Vitis vinifera L.) is one of the most widely cultivated white grape varieties in Chile, yet integrated studies addressing phenolic composition, polysaccharides, and color in commercial wines remain limited. This study characterized 30 commercial Chardonnay wines from major Chilean regions through a comprehensive analysis of phenolic composition, polysaccharide fractions, and CIELab color parameters, considering multiple sources of variability including vintage (2023–2024), closure type, geographic location, and valley of origin. Basic oenological parameters showed low variability, confirming their strong technological regulation in commercial wines. In contrast, total tannins, selected chromatic coordinates (particularly a* and hue angle), polysaccharide fractions, and several low-molecular-mass phenolics exhibited significant differences mainly associated with geographic origin and closure type. Among phenolic families, hydroxycinnamates, phenolic alcohols, and flavonols emerged as the most discriminant compositional domains. Multivariate analysis revealed that wine differentiation was structured by overlapping compositional gradients involving phenolic evolution, color expression, and polysaccharide composition rather than by vintage alone. Overall, the results highlight the multifactorial nature of Chardonnay wine composition and the combined contribution of grape origin, closure-associated bottle evolution, and winemaking factors. Nevertheless, because wines were commercially sourced and bottle age and storage conditions were not standardized, closure-associated differences should be interpreted cautiously as associations rather than causal effects.