A chemical survey of commercial Chilean Chardonnay wines: vintage-related variability in phenolic, polysaccharide, and color composition

Abstract

Chardonnay is the most widely planted international white grape variety, covering approximately 210,000 hectares worldwide and about 10,205 hectares in Chile (≈ 7.9 % of the national vineyard). Despite its relevance, integrated chemical surveys describing the compositional variability of commercial Chardonnay wines remain limited, particularly regarding the combined contribution of phenolic compounds, polysaccharides, and color parameters. This study presents a chemical survey of thirty commercial Chilean Chardonnay wines from two consecutive vintages (2023 and 2024) produced across contrasting wine regions. Wines were characterized through integrated physicochemical analyses including pH, total acidity, color intensity, CIELAB coordinates, total phenols, total tannins, four polysaccharide fractions according to molecular weight, total polysaccharides, and selected low-molecular-weight phenolic compounds. Global parameters were evaluated by spectrophotometric methods, while individual phenolics were quantified chromatographically. Results revealed pronounced compositional variability among wines and vintages. Total phenolic content ranged from approximately 200 to 460 mg gallic acid equivalents L^–1, while total polysaccharides showed wide dispersion, suggesting strong influences of regional origin and winemaking practices. Chromatic parameters were consistent with white wine matrices, displaying low color intensity and negative a* values; however, differences in b* and hue indicated variable oxidative evolution. Phenolic acids and flavan-3-ol derivatives contributed to chemical differentiation, whereas intermediate molecular weight polysaccharide fractions represented a major source of variability. Overall, the combined evaluation of phenolic composition, polysaccharide distribution, and color chemistry provides a robust analytical framework for assessing commercial Chardonnay wines and highlights the chemical heterogeneity associated with vintage and regional origin.

References

Gil i Cortiella, M; Ubeda, C., Covarrubias J.; Peña-Neira, A. (2020). Chemical, physical, and sensory attributes of Sauvignon blanc wine fermented in different kinds of vessels, Innovative Food Science & Emerging Technologies, 66: 102521.

Gil i Cortiella, M.; Ubeda, C.; Covarrubias, J.I.; Laurie, V.F.; Peña-Neira, Á. (2021). Chemical and Physical Implications of the Use of Alternative Vessels to Oak Barrels during the Production of White Wines. Molecules, 26, 554.