Unveiling the unknow aroma potential of Port wine fortification spirit taking advantage of the comprehensive two-dimensional gas chromatography

Although several studies investigated the impact of crop size or fruit zone microclimate on aromatic or phenolic composition of wines, the effects of these two practices were not assessed and compared in the same study through a technological experiment within the same vineyard. Therefore, their relative effectiveness is hard to compare, which in turn is essential for providing producers with valuable information as a basis to choose adequate approach in yield and canopy management. The aim of the study was to investigate the effects of two crop sizes and two different fruit zone microclimate conditions obtained by leaf removal in a two-factorial experiment, in order to assess and compare their relative impact on Istrian Malvasia (Vitis vinifera L.) white wine aroma and phenolic composition.

Viticulture is a major contributor to the antagonism of positive reputation and negative environmental impacts of agriculture. Vine contributes to structure landscape in the world, resulting, for example, in the delimitation of protected designations of origin (PDO). PDO vine is currently subject to the double challenge of sustainability and climate change adaptation. As vine is very sensitive to diseases and pests, vine requires a high use of pesticides to achieve its quality and yield goals. This high need for pesticides is the most important negative impact of environmental components.

Root system architecture (RSA) is important for soil exploration and edaphic resources acquisition by the plant, and thus contributes largely to its productivity and adaptation to environmental stresses, particularly soil water deficit. In grafted grapevine, while the degree of drought tolerance induced by the rootstock has been well documented in the vineyard, information about the underlying physiological processes, particularly at the root level, is scarce, due to the inherent difficulties in observing large root systems in situ. The objectives of this study were to determine genetic differences in the root architectural traits and their relationships to water uptake in two Vitis rootstocks genotypes (RGM, 140Ru) differing in their adaptation to drought. Young rootstocks grafted upon the Riesling variety were transplanted into cylindrical tubes and in 2D rhizotrons under two conditions, well watered and moderate water stress. Root traits were analyzed by digital imaging and the amount of transpired water was measured gravimetrically twice a week. Root phenotyping after 30 days reveal substantial variation in RSA traits between genotypes despite similar total root mass; the drought-tolerant 140Ru showed higher root length density in the deep layer, while the drought-sensitive RGM was characterised by shallow-angled root system development with more basal roots and a larger proportion of fine roots in the upper half of the tube. Water deficit affected canopy size and shoot mass to a greater extent than root development and architectural-related traits for both 140Ru and RGM, suggesting vertical distribution of roots was controlled by genotype rather than plasticity to soil water regime. The deeper root system of 140Ru as compared to RGM correlated with greater daily water uptake and sustained stomata opening under water-limited conditions but had little effect on above-ground growth. Our results highlight that grapevine rootstocks have constitutively distinct RSA phenotypes and that, in the context of climate change, those that develop an extensive root network at depth may provide a desirable advantage to the plant in coping with reduced water resources.

Occurrence of freezing temperatures in early spring when grapevine shoots are developing is termed late frost in viticulture. Young green tissues are very sensible to temperatures below zero and damages often lead to important yield and quality losses such as the case in Europe in 2017. An indirect method to avoid late frost damage in vineyards consist in delaying the budburst. Previous research reported similar effects by applying vegetal oil on dormant buds. Here, we tested the application of rapeseed vegetal oil during late winter to delay the budburst on two V.vinifera cultivars of interest in Austria, Grüner Veltliner (GV) and Zweigelt (ZW).

Non-Saccharomyces yeasts have been associated, for many years, with challenging alcoholic fermentation processes. However, during the last decade the use of non-Saccharomyces yeasts in wine production has become increasingly widespread due to the advantages they can offer in mixed inoculations with Saccharomyces cerevisiae (Sc). In this respect, Hanseniaspora vineae (Hv), in synergy with Saccharomyces spp, represents an interesting opportunity to impart a positive contribution to the aroma complexity of wines. In fact, it is a well-known producer of pleasant esters, such as 2-phenylethyl acetate. This study compares the performances of Hv (strain Hv-205) in sequential inoculation modality to Sc in three Chardonnay musts for base sparkling wine production. No significant differences were observed in basic chemical parameters between wines except for titratable acidity, with a significantly decrease (up to 1.5 g/L) in Hv processes due to malic acid degradation. The analysis of the aroma compounds revealed remarkable differences in concentration of volatile metabolites, among others up to 37-fold increase of 2-phenylethyl acetate. In contrast, lower concentration of its alcohol were detected, suggesting higher acetylation activity by Hv.