Yeast extract foliar spray elicits divergent aroma-phenolics profiles in ‘Cabernet Sauvignon’ and ‘Marselan’ grapes and wines

Foliar sprays of yeast extract (YE) at 1.67, 2.5, and 5 g/L were applied at 5 % véraison and again 10 days later to 'Cabernet Sauvignon' (CS) and 'Marselan' (MS) grown in eastern China. The 5 g/L YE treatment increased total norisoprenoids by 28 % in CS berries and by 82 % in MS, yet GC-MS quantification of 77 volatiles and OAV-based sensory reconstruction revealed contrasting effects: CS wines lost 29-42 % of ethyl isobutyrate, ethyl 2-methylbutyrate, ethyl acetate, and geranyl acetone, flattening fruity and floral perceptions, whereas the same esters increased 46-55 % in MS wines, intensifying ripe black-fruit notes. Anthocyanins responded divergently as well: four anthocyanins in CS skins rose 15-52 %, while five in MS declined 20-85 %. CIELab color metrics and partial least-squares regression confirmed concentration-dependent hue shifts. These findings support a targeted, cultivar-specific strategy for tailoring red-wine style and aroma structure under the terroir conditions of eastern China.