Incidence of trellis and training systems on the chromatic characteristics of wines from Sousón and Brancellao cultivars

Abstract

The phenolic profile, as determined by the relationship between different compounds, is characteristic of each grapevine variety and it is considered as a chemotaxonomic parameter for the classification and differentiation of red varieties of Vitis vinifera. However, this phenolic profile may vary significantly depending on the environmental and agronomic conditions. In this regard, differences in the anthocyanin profile as a result of agroecological factors have been recently reported. In this context, the aim of this study was to evaluate the influence of different training systems on the chromatic characteristics of two red grapevine Galician cultivars: Sousón and Brancellao. These varieties were grown under the same soil and climate conditions at the experimental farm of the Estación de Viticultura e Enoloxía de Galicia (EVEGA), within the D.O. Ribeiro (Ourense, Galicia, Spain). The vines, approximately 12 years old when this study began in 2010, were planted following two trellis systems (vertical shoot positioning and lyre) and four training systems (spurs, “ascendente portugués”, cazenave and sylvoz). Wines from these treatments were analysed for colour intensity; tonality; hue; contributions of yellow, red and blue components to wine colour; clarity; saturation and tone. In addition, total polyphenol index, total anthocyanin concentration and total tannin content were determined in the wines. For the overall of the three studied years (2010 to 2012), wine parameters presented certain trends among trellis systems. Although not significantly, alcoholic degre was lower in lyre than in the other systems for both Sousón and Brancellao. Other basic wine parameters such as titratable acidity and pH were very similar among trellis systems for both cultivars. Total polyphenol index for Brancellao was lower for sylvoz than for the other systems; whereas for Sousón it was greater for lyre and lower for “ascendente”. Anthocyanins presented a higher content under lyre for Brancellao but not for Sousón, where lyre presented the lowest content in anthocyanins. Tannins were very similar among systems for both cultivars.