Characterizing the Chemical and Sensory Profiles of United States Cabernet Sauvignon Wines and Blends

Abstract

Cabernet Sauvignon is one of the most reputable red grape varieties grown in the United States; however, limited information is available on the chemical and sensory composition of the resulting wines. The purpose of this study was to develop a rapid, targeted profiling method for measuring volatile compounds with sensory impact in U.S. Cabernet Sauvignon wines and blends. We developed a semiquantitative, automated headspace solid-phase microextraction (HS-SPME) gas chromatography–mass spectrometry (GC-MS) method combined with synchronous selected ion monitoring (SIM)/scan detection to measure 61 volatile compounds. The compounds monitored included grape-derived norisoprenoids and terpenes; fermentation-derived esters, higher alcohols, and aldehydes; Brettanomyces-related compounds; and oak-derived compounds. Methoxypyrazine was also measured using HS-SPME-GC-MS/MS. Twenty-four commercial U.S. Cabernet Sauvignon varietal and blended wines from several regions in California and Washington State were selected to encompass a broad range of wine styles and were analyzed using the GC methods developed. The results were compared to a descriptive sensory analysis of the wines using 11 trained assessors to determine the extent to which the chemical analyses could predict sensory profiles. The rapid, targeted profiling method was able to predict a number of aroma sensory descriptors. The Cabernet Sauvignon wines and blends differed in their chemical and sensory profiles and were differentiated, in part, as a result of the direct and indirect influences of varying alcohol levels. This work provides the wine industry with the ability to rapidly assess wine volatile composition in order to further elucidate the relationships between the chemical compounds and sensory profiles of wines.