Identification of Odor-Impact Compounds in Red Table Wines Produced from Frontenac Grapes

Abstract

Frontenac (Vitis spp. MN 1047) is a recently introduced, cold-hardy red winegrape that is currently the most-planted cultivar in much of the Upper Midwest. Through descriptive analysis, a set of aroma attributes common to red Frontenac table wines has been described, but the volatile compounds responsible for the characteristic sensory notes of the product have not been investigated. In order to identify these odor active compounds, eight Frontenac table wines were evaluated using stir bar sorptive extraction (SBSE) combined with concurrent gas chromatography/olfactometry-mass spectrometry (GC/O-MS). Eight panelists evaluated GC/O effluent using qualitative detection frequency analysis. Twenty-four volatiles were identified in odor regions perceived by panelists, including five alcohols, 14 esters, one lactone, two acids, and two volatile phenols. Twenty-three of these were confirmed by linear retention index data in separate GC-MS analyses, and 23 were quantified in runs using a known concentration of internal standard. Similar analyses of wines produced from V. riparia clone #89, a parent of Frontenac, found 16 volatiles common to Frontenac wines. A brief study of Frontenac juice with two days of skin contact suggested that four volatiles found in the wine may originate in the fruit.