Sensory, phenolic and volatile profiling of Malbec wines from different terroir of Mendoza

URVIETA, ROY; HEYMANN, HILDEGARDE ; BUSCEMA, F.; BOTTINI, R.; PICCOLI, P.; FONTANA, A.

Punta del Este

Congreso; 41st World Congress of Vine and Wine; 2018

The grapes from Mendoza, Argentina growth in regions with climatic and soils differences, from cold areas such as Tupungato with vineyards at 1600 m asl close to the Andes mountains, to warmer areas in the east of Mendoza at 500 m asl. In Argentina, the emblematic variety for red wines is Malbec with 40,434 ha, where 85.5% of the cultivated area is located in Mendoza province (www.inv.gov.ar, 2017).In the international and national market there is a wide range of prices and styles of wines, with the origin of the grapes, also called "terroir", as one of the main factors included in the definition of quality and price. This factor is important to the consumer, since it has an impact on the perception of quality and, therefore, on the price they are willing to pay (Famularo et al. 2010).In this sense, the identification of geographic origin and knowledge of the influence of chemical composition on sensory characteristics exerts an undoubted attraction from the commercial and scientific point of view. The objective of the present work was to study the influence of the geographical origin of Malbec grapes on the phenolic composition, profile of volatile compounds and sensory characteristics of Malbec wines from 28 parcels distributed across 6 regions of Mendoza, Argentina, while also searching for relationships between the sensory and chemical data profiles.Each parcel was selected to provide a representative sample of Malbec grapes in each location. The winemaking process was carried out in triplicate, using 800 L vessels under standardized conditions for all the parcels, and then the aging was in stainless steel tanks of 50 L. As for the determinations made, 33 phenolic compounds were analyzed and quantified using liquid chromatography with diode array detector (HPLC-DAD), and the volatile compounds were determined using solid phase microextraction (HS-SPME) and gas chromatography coupled to mass spectrometry (GC-MS). The sensory characteristics of the wines were analyzed 6 months after fermentation with 10 trained volunteers, who participated in an introduction to sensory analysis, generation of attributes, discussion, consensus on the reference standards and practice in the use of the scale. In total, 23 aromas, 4 flavors and 4 tactile sensations were evaluated in the mouth.The results showed that Malbec wines from different regions have sensory and chemical composition characteristics associated with their geographical origin. Nevertheless, there are sub-locations from San Carlos that has a huge variability in their wines. In fact, some sensory attributes and phenolics compounds of wines from this locations had similar intensity and quantities to those obtained in areas such as Luján de Cuyo. Other regions such as Rivadavia and Maipú are well separated using the sensory profiles, but there are no differences between them using the phenolics profiles. The sensory results are similar to those reported in previous studies (Urvieta et al. 2018), but a different discrimination of the regions using phenolic data was observed, which could be due to a vintage effect that would add variability in each region. To study the relationship between sensory and chemical data, PLS regression was used. These plot showed that certain descriptors are associated with phenolic and volatile compounds. This is the first work for Malbec that includes data on phenolic compounds, volatile compounds and sensory characteristics in an integral way, including the most important regions of Argentina in terms of quantity but specially on quality of its production.