Are biochemical markers the key to predicting wine aroma balance?

Abstract

Wine aroma quality is a complex interplay of factors like terroir, vinification techniques, that modulate aroma compound composition. Nowadays, due to the versatility of stringent climatic conditions, complex dynamic changes in volatile profiles shaped by cultivar and ripening stage highlight the need for advanced analytical tools to fully explore and predict aroma balance. Thus, integrative strategies using diverse cultivars under field conditions are essential to assess the aromatic matrix and identify biomarkers to manage aroma profiles across harvest dates, particularly in climate-sensitive cultivars. While targeted is often used with a limited number of cultivars to evaluate the impact of maturation conditions on the composition and sensory balance of the wine we propose to explore the potentiality of non-targeted analysis.

We studied musts and wines from eight Vitis vinifera cultivars (VITADAPT program, 2022 vintage): Cabernet franc, Cabernet Sauvignon, Carménère, Castets, Cot, Merlot, Petit Verdot, and Touriga Nacional. Grapes were harvested at five stages (mid-veraison, half-maturity, 7 days before maturity, maturity, and 10 days post-maturity). Samples were analysed by headspace solid-phase microextraction (HS-SPME) combined with comprehensive two-dimensional gas chromatography and time-of-flight mass spectrometry (GC×GC-TOF/MS). Deconvolution of chromatogram produced approximately 20000 signatures in must and around 10100 in wine. Thanks to a scrip developed on R we identified 40–150 and 200–300 significant compounds, respectively, depending on the cultivar. Aldehydes, ketones, and terpenes showed the most pronounced shifts in must, while esters and lactones prevailed in wine, shaping the aroma profile. Mathematical modelling provided a deep understanding of the kinetics of these compounds, uncovering critical interactions and dynamics within chemical families. This approach not only enhances our ability to decode the complex biochemical processes underlying aroma development but also offers a robust framework for optimizing vineyard management and winemaking strategies.