Landscapes of Vines and Wines Patrimony – Stakes – Valorisation

Carbonic Maceration (CM) winemaking is typically used in different European regions. But It is paradoxical that being a traditional processing system and widely used in many wineries, some of the phenomena that take place and the parameters that characterize them are barely known. In this vinification system the intact grape clusters are placed in a carbon dioxide (CO2) enriched medium, and they immediately change from a respiratory metabolism to an anaerobic fermentative metabolism called intracellular fermentation, which is carried out by grape enzymes. But some grapes located in the lower zone of the tank are crushed by the weight of the ones above and release must, which is fermented by yeasts.

AIM. Grape seeds (Vitis vinifera) are among the main constituents of grape pomace, also exploited in ingredients for nutraceutics and cosmeceutics, particularly regarding the phenolic fraction. The macromolecules of grape/wine include polyphenols, proteins and polysaccharides.

Proton relaxation in model and real wines was investigated by fast field cycling NMR relaxometry. Albeit protons of wine are largely belonging to water molecules, their magnetic relaxation rates actually depend on various physico-chemical parameters related to the state of the wine and to its composition.

The use of rootstocks tolerant to soil water deficit is an interesting strategy to cope with limited water availability. Currently, several nurseries are breeding new genotypes, but the physiological basis of its responses under water stress are largely unknown. To this end, an ecophysiological assessment of the conventional 110-Richter (110R) and SO4, and the new M1 and M4 rootstocks was carried out in potted ungrafted plants. During one season, these Vitis genotypes were grown under greenhouse conditions and subjected to two water regimes, well-watered and water deficit. Water potentials of plants under water deficit down to < -1.4 MPa, and net photosynthesis (AN) <5 μmol m-2 s-1 did not cause leaf oxidative stress damage compared to well-watered conditions in any of the genotypes. The antioxidant capacity was sufficient to neutralize the mild oxidative stress suffered. Under both treatments, gravimetric differences in daily water use were observed among genotypes, leading to differences in the biomass of root, shoot and leaf. Under well-watered conditions, SO4 and 110R were the most vigorous and M1 and M4 the least. However, under water stress, SO4 exhibited the greatest reduction in biomass while M4 showed the lowest. Remarkably, under these conditions, SO4 reached the least negative stem water potential (Ψstem), while M1 reduced stomatal conductance (gs) and AN the most. In addition, SO4 and M1 genotypes also showed the highest and lowest hydraulic conductance values, respectively. Our results suggest that there are differences in water use regulation among genotypes, not only attributed to differences in stomatal regulation or intrinsic water use efficiency at the leaf level. Therefore, because no differences in canopy-to-root ratio were achieved, it is hypothesized that xylem vessel anatomical differences may be driving the reported differences among rootstocks performance. Results demonstrate that each Vitis rootstock differs in its ecophysiological responses under water stress.

AIM: In the last years, many wineries are increasing experimentation to produce more distinguishable beverages. In this sense, the reduction of the fermentation temperature could be a useful tool because it preserves volatile compounds and prevents wines from browning, particularly in the case of white wines.