Analysis of Carotenoids in Grapes To Predict Norisoprenoid Varietal Aroma of Wines from Apulia

To determine a correlation between carotenoid precursors in grapes and norisoprenoid varietal aroma of wine, carotenoids were identified and quantified by HPLC-DAD-MS (ESI+) from four representative wine grape varieties of the Apulian region (Chardonnay, Merlot, Negroamaro, Primitivo) in two years of study (2006-2007), and C-13-norisoprenoid aroma potential, Delta C (mu g/kg), was calculated from the difference of total carotenoid concentration between veraison and maturity. C-13-norisoprenoids were analyzed by GC-MS in the obtained wines from 2006 and 2007 vintages. Higher Delta C values, found in Chardonnay and Merlot grapes, corresponded to higher norisoprenoid contents in the respective wines, particularly characterized by highly flavorant compounds such as beta-damascenone and 3-oxo-alpha-ionol. A linear regression was determined that was significant at the 0.01% level (F = 36.12, p = 0.00096) with R = 0.9261, between grape Delta C values and total norisoprenoid contents in wine. These findings support the hypothesis that Delta C could be a useful technological tool to predict norisoprenoid aroma of wine and, consequently, to identify grapes with higher aroma potential.