Genetic variation among wild grapes native to Japan

Condensed grape tannins play a major role in the organoleptic properties and quality of red wine. Recently, a new sub-family of macrocyclic condensed tannins has been identified in red wine and named “crown tannins”. Indeed, the first compound of the family identified and characterised by NMR was the crown procyanidin tetramer which is composed of a macrocyclic structure composed of four (-)-epicatechins link together by B-type interflavanoid linkage in the following an alternative sequences of C4-C8 and C4-C6 linkage. The 3D structure of this unusual crown procyanidin family reveals a central cavity in the molecule [1].

In grapevine, phenology from bud break to berry maturation, depends on temperature and water availability. Increases in average temperatures accelerates initiation of bud break, exposing newly formed shoots to detrimental environmental stresses. It is therefore essential to identify genotypes that could delay phenology in order to adapt to the environment. The use of different rootstocks has been applied to change scion’s characteristics, to adapt and resist to abiotic and biotic stresses[1].

The barrel-making process is widely recognized as a crucial practice that affects the composition of barrel-aged wine. After the drying process, the staves are considered ready for barrel assembly, which includes the processes of bending and toasting the barrel structure. Toasting is considered one of the most critical stages in determining the physical and chemical composition of the staves, which can influence the chemical and sensory composition of the wine aged in barrels made from them [1].

During red wine fermentation, the extraction of phenolics compounds and sufficient oxygen provision are critical for wine quality [1,2]. In this trial, we aimed at evaluating the kinetics of phenolic extraction and dissolved oxygen during red wine fermentations using the airmixing system. Twenty lots of red grape musts were fermented in 300.000 L tanks, equipped with airmixing, using two injection regimes (i.e., high and low intensity, and high and low daily frequency). An oxygen analyzer was introduced into the tanks in order to record the concentration of dissolved oxygen over time.

Wine produced under Designation of Origin (DOP) Ribeiro, the oldest DOP in Galicia (NW Spain), are elaborated using local grape cultivars, grown at the valleys of Miño, Avia and Arnoia rivers. The landscape formed by slopes and terraces and the peculiar climate of continental character, softened by the proximity of Atlantic Ocean, make it an area of excellent aptitude for vine cultivation. In addition, small-scale farming and the use of traditional techniques for vineyard management provide a great diversity to Ribeiro wines. This study presents the evaluation of red and white wines (bottled or bulk wines) from DOP Ribeiro, produced between years 2018-2022.