Location effects on ripening and grape phenolic composition of eight 'Carignan' vineyards from Maule Valley (Chile)

Gastón Gutiérrez-Gamboa1, 2, and Yerko Moreno-Simunovic1*
Among the forgotten varieties within the Chilean wine industry, 'Carignan' grapevines (Vitis vinifera L.) in the Maule Valley, Chile, have been rediscovered by viticulturist and winemakers, producing very interesting wines and well recognized worldwide. Phenolic compounds are secondary metabolites, and there has been much interest in potential health benefits of polyphenols as antioxidants. The aim of this work was to study grape phenolic composition from 'Carignan' vineyards growing in eight different sites of the Maule Valley during the 2016 vintage. Phenolic compounds were analyzed by HPLC-DAD. The results showed that, as expected, the most abundant anthocyanin, flavonol, flavanol and hydroxycinnamic acid in 'Carignan' grapes were malvidin-3-glc varying from 279.56 to 428.68 mg kg-1, quercetin-3-glucoside+rutin ranging from 27.64 to 82.69 mg kg-1, procyanidin B1 varying from 39.13 to 72.84 mg kg-1 and trans-coutaric acid varying from 27.14 to 72.76 mg kg-1, respectively. trans-Piceid was the only stilbene identified, which ranged from 1.06 to 7.67 mg kg-1. Climate conditions more than soil characteristics affected grape ripening. Generally, grapes from Curtiduría (Cur) and El Peumal (Peu) presented a faster ripening, in terms of technological maturity, than grapes harvested from the rest of the sites, regarding day of season. In most of the phenolic compounds, grapes from Peu, presented higher concentration than grapes from the rest of the sites. Thus, location conditioned phenolic composition in grapes. These findings are of importance for the Chilean wine industry in relation to the viticultural management of the 'Carignan' variety, regarding climatic conditions, soil characteristics and ripening within the Maule Valley.
Keywords: 'Carignan', climatic conditions, Maule Valley, rainfed, ripening, soil characteristics, Vitis vinifera.
1Universidad de Talca, Facultad de Ciencias Agrarias, Av. Lircay S/N, Talca, Chile. *Corresponding author (ymoreno@utalca.cl).
2Instituto de Ciencias de la Vid y del Vino (CSIC-CAR-UR), Ctra. de Burgos km 6, 26007 Logroño, España.