Vegetative dose heights ‘Cabernet Sauvignon’ and its influence on fruit and wine quality

Deficit irrigation is a viticultural practice often applied to improve the phenolic composition of red grapes and wines. However, the impact of this practice on grape terpenes – key aromatics for several grapes and wines – remains largely unknown. This study investigated the impact of deficit irrigation strategies on free and glycosylated terpenes in Gewürztraminer grapes. In a field study conducted in Oliver, BC, in 2016, 2017, and 2018, deficit irrigation regimes were applied to Gewürztraminer vines at different developmental stages (pre-veraison = Early Deficit, ED; post-veraison = Late Deficit, LD; throughout the season = Prolonged Deficit, PD). A well-irrigated control (CN) treatment was also established.

Climate change is driving global temperatures up together with a reduction of rainfall, posing a risk to grape yields, wine quality, and threatening the historical viticulture areas of Europe.

Wine aroma represents one of the most important quality parameter and it is influenced by various factors (viticulture and vinification techniques, climate or storage conditions etc.). Wines produced from conventionally and ecologically grown grapes of same variety have different chemical composition and aroma profile [1]. Aroma profile of wine can be also influenced by additional treatment of wine, such as concentration of wine by reverse osmosis (RO). Reverse osmosis represents a pressure-driven membrane separation technique that separates the initial wine on the retentate or concentrate that is retained on the membrane, and permeate that passes through it [2]. Wine permeate usually containes water, ethanol, acetic acid and several low molecular weight compounds that can pass through the membrane. This property enables the use of reverse osmosis membranes for wine concentration, partial dealcoholization, acetic acid or aroma correction [3,4].

More recently, studies have shown that polyphenols could also prevent or improve vision in patients with ocular diseases and especially age-related macular degeneration (AMD) which is an eye disease characterized by damage to the central part of the retina, the macula, and that affects millions of people worldwide. Despite therapeutic advances thanks to the use of anti-vascular endothelial growth factor (VEGF), many resistance mechanisms have been found to accentuate the visual deficit.

A novel and efficient Dispersive Liquid-Liquid Microextraction (DLLME) method coupled with gas chromatography–mass spectrometry (GC–MS) was developed to determine 33 key aroma compounds (esters, alcohols, aldehydes, terpenes, norisoprenoids, fatty acids and phenols) present in Pinot noir (PN) wine. Four critical parameters including extraction solvent type, disperse solvent type, extraction solvent volume and disperse solvent volume were optimised with the aid of D-optimal design.