Where does the wine go experiencing regulated deficit irrigation: the effect of RDI on volatile composition and the sensory properties of Cabernet Sauvignon wines

Cabernet Sauvignon grapevines are treated with different degrees of water deficit during pre-veraison and post-veraison, and the fruits are brewed into wines after ripening. Where does the wine go experiencing regulated deficit irrigation (RDI)? The study addresses the selection of timing and extent of RDI from the perspective of volatile composition and wine sensory quality, the color parameters is characterized through using the CIELAB color space, the content of volatile compounds is determined by GC-MS and wine aroma style recognition is qualitatively and quantitatively expressed by the combined application of principal component analysis (PCA), hierarchical cluster analysis (HCA) and GB/T 16861-1997 “Sensory Analysis: Identification and Selection of Descriptors for Building sensory Profiles through Multivariate Analysis”. The irrigation amount during post-veraison plays a more critical role compared to the pre-veraison, with its variation significantly impacting in the composition and content of volatile compounds of the wine, and ultimately formed different wine styles. Linalool, phenethyl acetate and 1-heptanol are common upregulated differential metabolites among all RDI treatments, while ethyl butyrate and ethyl hexanoate mean common down-regulating, among all the groups, 8060P treatment is most conducive to the improvement of fruit flavor and the reduction of green flavor, demonstrating better improvement in sensory style, while taking into account the preservation of wine color, and also realize water-saving irrigation, which is the most appropriate treatment in this experiment.