Updating the Winkler index: An analysis of Cabernet sauvignon in Napa Valley’s varied and changing climate

L’identification des produits par le nom de la ville, de la région, de la province d’origine d’un produit tend aujourd’hui à se développer partout dans le monde et notamment dans le secteur agro-alimentaire, mais aussi dans les secteurs des produits artisanaux.

AIM: Wine consumption in the last fifteen years showed a decrease in Europe [1]. New alternatives of wines appeared on the market. Those beverages are obtained by blending wines and fruit juices or flavoring wines with artificial or natural aromas and have medium alcohol content (from 8 to 10.5%) [2]. Recently, an innovative fruit wine has been proposed obtained by co-fermenting grape must and kiwi juice [3] whose potential attractiveness to consumers should be exploited. However, differences in product acceptability and perception, as well as the individuals’ willingness to consume and pay could change in function of subjects socio-demographic characteristics. The target group selected is represented by young adults (18-35 years old) consumption groups.

Botrytis cinerea is a fungus that causes common infection in grapes and other fruits. In winemaking, its presence can be both considered desirable in the case of noble rot infection or undesirable when grey rot is developed. This fungus produces an extracellular enzyme known as laccase which is able to cause oxidation of phenolic compounds present in must and wine, causing most of the times a decrease in its quality and problems during the winemaking process [1]. Material and methods: Three B. cinerea strains (B0510, VA612 and RM344) were selected and grown in a liquid medium adapted from one previously described [2]. The enzyme was isolated by tangential ultrafiltration of the culture medium using a QuixStand system equipped with a 30 KDa filtration membrane.

During the more than 190 years since the founding of the first ampelographic collection, the creation of a series of collections is attested on the territory of the Republic of Moldova, each operating in different historical periods and socio-economic 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.