Comprehensive analysis of volatile composition and sensory properties of wines from Guankou grape (Niagara) produced by five winemaking technologies

As a “foxy” grape cultivar, Niagara grapes grown in Jianshi County, China, have developed distinctive sensory and stylistic characteristics shaped by local environment, and are locally known as the “Guankou grape”. This study evaluated the volatile profiles and sensory characteristics of Guankou wine produced using five winemaking methods: dry wine using the traditional dry white winemaking process (DW), dry wine from must with added sugar and tartaric acid (DSA), dry wine from cold-macerated must (CDW), dry wine from cold-macerated must with added sugar and tartaric acid (CDSA), and sweet wine from must with membrane filtration (SWM). Among the 28 compounds with an odor activity value (OAV) > 1, six compounds exhibited OAVs > 100—four esters and two alcohols. These compounds collectively define the core aroma of Guankou wine: esters bring notes of tropical fruits, apple, and pear, while alcohols contribute banana, fermented, and spicy aromas. Sensory analysis showed DSA had the highest visual clarity and flavor intensity scores, DW had the highest aroma intensity score. The CDSA was preferred for enhancing wine flavor, while membrane filtration should be used cautiously in sweet wine production to avoid aroma loss and sensory quality decline. • The winemaking potential of Guankou grape, a "foxy" grape variety, was analyzed. • Six key compounds (4 esters, 2 alcohols) with OAV > 100 define Guankou (Niagara) wine’s core "foxy" aroma. • Five discriminative aroma markers are identified via PLS-DA to distinguish five winemaking processes. • Cold-macerated must with added sugar and acid increases the aroma complexity. • Esters and alcohols are the main contributors to aromatic characteristics.