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

Aim: To investigate the interaction effects between irrigation and crop load and the resulting impact on grape heterogeneity within a Geographical Indication in South Australia. 

Methods and Results: Cabernet Sauvignon grapes were sampled at the time of harvest from the Coonawarra

Oxidative stability is a critical factor in maintaining wine quality during its shelf-life. SO₂ is commonly added to wine due to its strong antioxidant activity, although there is a general push to reduce SO₂ use in vinification.

Le climat a de fortes implications sur le bon fonctionnement physiologique de la vigne et a besoin d’être quantifié afin de déterminer l’aptitude des régions à la culture de la vigne. Une méthode, qui pourrait éventuellement servir à prévoir l’aptitude des régions à la culture de la vigne, est proposée.

(-)-Rotundone, an oxygenated sesquiterpene, is a potent odorant molecule with a characteristic spicy aroma existing in various plants including grapes1. It is considered as a significant compound notably in wines and grapes because of its low sensory threshold (16 ng L-1 in red wine, 8 ng L-1 in water) and aroma properties. (-)-Rotundone was first identified in red wine made from the grape cultivar Syrah (regionally called Shiraz) in Australia1, and then it was found in several grape varieties such as Duras, Grüner Veltliner, Schioppettino and Vespolina from Europe2, 3. Several environmental factors affecting the accumulation of (-)-Rotundone during the grape maturation, were reported such as ambient temperature4, soil properties and topography5, soil moisture from irrigation and light exposure in the bunch zone by leaf removal2.

The capture and valorization of fermentative CO2 have been developed for several years by the company w platform for internal uses, notably in the cellars: inerting, cooling, reduction of water consumption, extraction, with aroma valorization. In a context of climatic warming during the vegetative cycle, grapes are currently harvested with a significant sugar concentration, a phenomenon that is expected to intensify in the coming decades. The high alcohol content of the resulting wines goes against the demand of customers who are seeking high-quality wines with less alcohol.