Investigation on harvesting period choices for correct interpretation of experimental results

In recent years, consumer demand for products without chemical additives increased, becoming a priority for the wine sector. SO₂ is widely used for its multiple properties including antiseptics, antioxidants and antioxidasics and the strategy of bioprotection in winemaking represents now an alternative to this chemical additive. In oenology, results have highlighted the interest of bioprotection to limit the development of microorganisms like Hanseniaspora uvarum and thus reduce the doses of sulphite. Indeed, this species is considered because of its acetic acid and methyl butyl acetate production, the latter can cover the varietal character of wines.

The important grape variety Welschriesling for Austrian and Southeast European viticulture has been selectively bred over the years for improving some quantitative traits. Collected genotypes as well as the local clones were examined from agricultural, analytical, sensory, and genetic perspectives.

It is well documented that varietal aroma is an important parameter of wine quality. Chemical compounds responsible for wine varietal aroma are sourced from secondary grape metabolites. Until today little research is conducted on the influence of vine clone on the grape aromatic content of Greek grape varieties. Xinomavro (Vitis vinifera L.) is one of the most important Greek grape varieties, valuable for the wine industry of Northern Greece since it contributes to the production of PDO wine of Naoussa, Amindeo and Goumenissa.

The Douro demarcated region constitutes just over 50% of the area of mountain vineyard in the world, i.e., vineyards with slope gradients of 30% or above. Among the different (terraced) vineyard layouts, the formerly preferred wider terraces supporting two rows of vines and the currently advocated narrower single vine row, dominate the vineyards’ planting layout. The slope of these terraces, in other words, the supporting earth ramp, is a key element in these vineyards’ construction.

White wine protein haze can be prevented by removing the grape juice proteins, currently achieved by bentonite addition. To avoid wine volume loss and to minimizes aroma stripping, degrading haze-forming proteins in wine with proteases is a particularly interesting alternative to bentonite. In the present study, two fungal proteases treatments combined with different heating (50, 60, 72 °C) + refreshing steps, were applied on Gewürztraminer grape juice, and compared to bentonite treatments. The impact of these 19 treatments on the wine haze risks was determined by using two heat tests at 50 °C (heating during 30 to 120 min) and 80 °C (heating during 5 to 60 min). The protein contents and compositions were also estimated using the SDS-PAGE + densitometric integration techniques.