Hplc-ms analysis of carotenoids as potential precursors for 1,1,6-trimethyl-1,2-dihydronaphthalene (TDN) in riesling grapes

The phenolic compounds (cathechins, cynnamic acids, anthocyanidins) in wines made from 6 vine-varieties (Sangiovese, Cabernet S., Nero d’Avola, Foglia Tonda, Pinot N., Mazzese) grown in 4 different pedoclimatic zones of Tuscany (Arezzo, Grosseto, Pisa and Lucca) have been analyzed by HPLC.

Drought stress has a profound impact on grapevine productivity and significantly alters key quality-related traits of berries. Although research has been conducted on the effects of individual drought events, there is still a knowledge gap regarding the cumulative consequences of repeated exposure to water scarcity and the influence of the timing of stress imposition. To address this gap, a field experiment was conducted to investigate the impacts of repeated drought stress on yield, berry composition, and the phenolic profile of grape berries. The results indicate that yield is primarily influenced by pre-veraison water deficit. Although the number of clusters was only slightly reduced, a substantial decrease in berry size was observed, resulting in a notable reduction in overall yield.

During Champagne or sparkling wine tasting, gas-phase CO2 and volatile organic compounds invade the headspace above glasses [1], thus progressively modifying the chemical space perceived by the consumer. Gas-phase CO2 in excess can even cause a very unpleasant tingling sensation perturbing both ortho- and retronasal olfactory perception [2]. Monitoring as accurately as possible the level of gas-phase CO2 above glasses is therefore a challenge of importance aimed at better understanding the close relationship between the release of CO2 and a collection of various tasting parameters.

Merlot grapevine is the second wine cultivar most planted in the world and especially in the Bordeaux wine region. This cultivar has many advantages in producing high quality wine; however, in the last decade, climate change has increased the sugar concentration in berries at harvest and shortened the maturation cycle. If this has been up to now a great opportunity to improve wine quality profile, we are touching the tipping point. High sugar concentration at harvest induces high alcool content in wine which can negatively impact wine quality. There are many viticultural and oenological practices possible to limit this effect. In this study we focus on plant material through intra-varietal diversity of Merlot cultivar.

Air temperature is arguably one of the most decisive factors for winegrape varieties developmental cycle, ripening potential and yield.