Catherine Dadmun, Anna Katharine Mansfield,* and Hans Walter-Peterson
*Cornell University, 665 W North St, Geneva, NY 14456 (akm87@cornell.edu)

Interspecific hybrid winegrapes are economically important in areas where environmental pressures inhibit traditional Vitis vinifera production. Red hybrid grapes, however, show great diversity in anthocyanin profile, and viticultural and winemaking techniques that optimize color in red V. vinifera wines are often ineffective for hybrid wine production. Because the chemistry of hybrid grape anthocyanins is largely unknown, the reactions they undergo during ripening, wine production, and aging are poorly understood. To clarify the effect of vine microclimate on red hybrid wine color, anthocyanin profiles were assessed for shaded and unshaded fruit from three economically significant cool-climate hybrid cultivars (Vitis spp): Corot noir, Maréchal Foch, and Marquette. Berry samples were collected throughout ripening from triplicate blocks of each cultivar grown in the New York Finger Lakes region, then skin extract anthocyanins were characterized using high-performance liquid chromatography analysis. Tentative anthocyanin identifications were confirmed via mass spectrometry. Light exposure and berry and air temperature were monitored in Corot noir throughout the season to represent generalized vine microclimate. Across all cultivars, the samples that underwent the leaf-pulling treatment (exposed samples) had total anthocyanin concentrations that were not significantly different from the control (shaded samples). However, certain individual anthocyanins within each cultivar demonstrated different concentrations with the exposure treatment. This work is the first step in defining the evolution of anthocyanin profiles during interspecific hybrid grape ripening to allow cool-climate winegrape growers to optimize viticultural production methods for high-quality red hybrid wines.

Funding Support: The Cornell Agritech (New York State Agricultural Experiment Station) Research Venture Grant