Volatile composition of Bonarda wines from different geographical zones of Mendoza (Argentina)

Abstract

Bonarda (Vitis vinifera L.), also known as Corbeau, is the second most cultivated red grape variety after Malbec in Argentina. This cultivar is widely distributed in different regions of this country, highlighting Mendoza province with over 84% of the total. Despite its economic and cultural importance, there is little information about the influence of agro-ecological and technological factors on their chemical composition. The aim of this study was to analyze and characterize the volatile composition of Bonarda wines from different geographical zones of Mendoza. During the 2016 season, grapes from 16 viticultural locations were harvested in triplicate and made into wine in scale-pilot following a standard protocol. After malolactic fermentation, general analytical parameters were determined in wines by the official methods of OIV, and individual volatile compounds were analyzed by HS-SPME/GC-MS. Thus, thirty-six volatile compounds were identified in Bonarda wines. Esters was the most numerous chemical group, however, alcohols presented the highest total amounts. In general, the wines evaluated presented similar levels of alcohol, pH, and total acidity, highlighting Tupungato whose wines showed lower alcohol and pH, and higher acidity respect to the rest. The classification of wine samples using chemical data and multivariate methods has been achieved successfully. It must be emphasized that the discriminant analysis yielded an unambiguous classification of samples according to the geographical zone, which clearly demonstrates the high potential of aroma-based analysis for Bonarda differentiation. This outcome could be regarded as an additional criterion for studies pertaining to Bonarda quality control and authenticity.