Characterizing the molecular basis of the differences in aromatic precursors found in commercial clones of Vitis vinifera cv. Tannat

Une variable composite, dénommée Indice de Site (SI), intégrant les propriétés physiques du sol et le mésoclimat, avait été proposée pour caractériser les terroirs dans le cadre d’une étude des vignobles de Cabernet Sauvignon de Hawke’s Bay en Nouvelle Zélande.

The spatial distribution of powdery mildew is often heterogeneous between neighboring plots, with higher disease pressure in certain places

Grapes infected with grey mould due Botrytis cinerea are widespread in vineyards during certain growing conditions.

Mint aromas in wine, which manifest as “cool” or “fresh” character, can originate from different chemical classes, one of which is the terpenoids. A broadly diverse, naturally occurring class of chemical compounds, terpenes possess wide applications across multiple industries due to their pharmaceutical, antiseptic, medical, and aromatic properties. Monoterpenes, a subclass of terpenoids, likewise play a major role in wine sensory perception. Within the monoterpenes, those possessing “mint” odor qualities have often been studied in the context of “vegetal” or “herbal” wine faults; however, their role in positive aromatic evolution is less understood. Yet an extensive 2015 study of older premium Bordeaux red wines identified mint as a contributing factor in quality bouquet development. From that point, it was necessary to investigate the origins of those monoterpenes as well as the chemical conditions required for their development during ageing. Those two key points could finally facilitate predicting the apparition of minty character in older wines based on their composition while young.
A principal contributor is the cyclic monoterpene limonene, which was isolated relatively early in grapes and wine. Not only does limonene itself possess a cool, fresh odor, it is also a precursor for, and possible derivative of, additional mint monoterpenes. Among the most commonly found monoterpenes, limonene and its derivatives can constitute the majority of the essential oils of citrus fruits, mint and herb plants, and coniferous trees. Many of these mint monoterpenes also occur in grapes and wine. With aromas ranging from woody and earthy to citrus to mint and herbaceous, their contribution to wine is potentially diverse and multi-faceted. While sometimes, found at concentrations below the sensory threshold, synergistic effects between these molecules could render them perceivable.
This review looks at limonene and its transformation as studied in different matrices, and potential parallels or analogues in wine. Moreover, within the complex kinetics of wine aging, the relative concentrations of mint monoterpenes appears to continue to evolve and change, with additional evidence from model wine solutions suggesting they may even revert to their originating precursors. Continued study of mint monoterpenes and their role in wine aromatics will contribute to a deeper understanding of the development of aging bouquet and the longevity of premium wines.

Biodiversity loss in agrosystems is partly due to landscape simplification (field enlargement, hedgerows removal…) that led to a loss of heterogeneity of the overall landscape.