PHENOLIC PROFILING OF MALBEC WINES FROM MENDOZA: INFLUENCE OF SOURCE ORIGIN

URVIETA, ROY; FONTANA, A.; BOTTINI, R.; BUSCEMA, F.

Rosario

Simposio; 2nd Latin American Metabolic Profiling Symposium; 2016

Malbec is the most cultivated variety in Argentina with 34.559 ha in Mendoza1. In the international market a wide price gap of Malbec wines can be found, and one of the most important factor defining the quality and final prices is the origin of the grapes, also denominated with the name of terroir. The concept of terroir in viticulture refers to a complex interplay of factors, covering the vine and its surrounding environment, highlighting the importance of local vineyard climate, soils, vegetal material, along with human intervention2. Mendoza environmental conditions are highly variable within its territory, from cold areas as Gualtallary in Tupungato, to warmer areas such as the east of Mendoza. Phenolic compounds are products of secondary metabolism that are present in the vacuoles of berry skins and are extracted during vinification3. The concentration and profiling of phenolic compounds can be used as markers of the source of origin of wines, giving information about the terroir.The main objective of the present study was to investigate the influence of geographical location on phenolic composition of Malbec from twenty-five parcels distributed in six regions of Mendoza, Argentina. Each parcel was selected based on their uniformity and regional representativeness, using the same winemaking technique in the winery without oak aging. Anthocyanins and non-anthocyanins phenolic compounds were analyzed by HPLC-UV after six months of bottle aging. The results were analyzed using chemometrics for the thirty quantified phenolic compounds. Results demonstrate that Mendoza Malbec wines have common compositions related to geographic origin. In the first zone and the Uco Valley, wines from different appellation have similar phenolics profile, and the wines of east zone are separated from the other two regions. Discriminating by department, similar characteristics for San Carlos and Luján de Cuyo were obtained, Tunuyán and Tupungato were close, while the departments of Maipú and Rivadavia were clearly differenced. By performing a cluster analysis, a wide variability in the profiles of phenolic compounds of wines from each region was observed, where parcels located in the same lot of a vineyard are so different between each, but can be assimilated to wines that are in other region. According to achieved results, the actual terroir denomination in Mendoza defined with political limits may not be the best way for classification of wines, because a great influence of climatic and soil characteristics of each parcel were observed.