Multidimensional Characterization of Astringency Quality in Dry Red Wine and Its Effects

The astringency analysis method for dry red wine was designed by considering the time dependence of astringency, the sub-quality attributes of oral sensation and the instant facial expressions of panelists, so as to provide the methodological support for the multidimensional characterization of astringency quality.

Astringency time dependence of dry red wine was characterized by the time intensity method, and the related parameters were measured, such as maximum astringency intensity (Imax), rate of intensity increase before Imax (Vi), rate of intensity decrease after Imax (Vd), area under the curve (AUC), and perception duration (Ttot). Astringency sub-qualities, such as drying, rough, and pucker, were evaluated using CATA and TDS methods. Likability of the wine was analyzed through immediate facial expressions. Twenty-seven Cabernet Sauvignon dry red wine samples from Gansu, Ningxia and Xinjiang were used to characterize the astringency intensity, sub-quality characteristics and perceived differences in liking.

Significant variations in astringency were observed among the three regions, particularly in Imax, Vd, and AUC. Wine samples from Ningxia exhibited the highest values for Imax, AUC, and Vd compared to those from Gansu and Xinjiang. The sub-qualities of astringency, such as drying, numbing, rough, pucker, green, and grainy, were frequently identified, with a frequency exceeding 50%. These sub-qualities constituted the main attributes of astringency in the analyzed wines. Correlation analysis of multiple astringency indexes revealed that the astringency sub-qualities in dry red wines from the three regions primarily consisted of rough, pucker, and drying. Excessive roughness and numbing diminished positive emotions among panelists, while the graininess often elicited happy and surprised expressions. Principal component analysis (PCA) of the multivariate data on astringency in the sampled wines demonstrated that the multidimensional characterization technology method designed in this study had a strong ability to distinguish astringency of sampled wines. Wine samples from Ningxia had higher Imax, AUC, Vi, and Vd, while the rough, pucker, drying and numbing were more obvious. Xinjiang wine samples had stronger grainy sense, and the Imax, AUC, green and numbing were weaker, but the drinking comfort was better. The wine samples from Gansu had the strongest green astringency and the weakest rough dominance rate.

The multidimensional characterization method for dry red wine developed in this study effectively captured the diversity of astringency in a concrete and detailed manner, which provided a more scientific evaluation of astringency differences, making it valuable for broader application and promotion.