Study of the phenolic composition of Vernaccia di San Gimignano vine

CREA, Research Centre for Viticulture and Enology, 52100 Arezzo, Italy

^* Corresponding author: franco.giannetti@crea.gov.it

Abstract

Vernaccia di San Gimignano is a Tuscan white wine, with a great historical tradition, produced mostly from the homonymous grapevine. One of the peculiarities of the vine, apart from producing fruity and sapid young wines, is the ability to generate structured wines, suitable for the aging process of “riserva” type. For a better understanding of the Vernaccia di San Gimignano characteristics, a research protocol has been set up. It specifically concerns the phenolic composition of the grapes observed by HPLC analysis. The hydroxycinnamic acids, the flavanols and the flavonols of the skins, the flavanols of the seeds and the hydroxycinnamic acids of the juice have been determined. The trans-caftaric acid is the predominant form in the juice (70-120 mg/L) and in the skins (5-12 mg/Kg) where there are higher values of quercetin (4-20 mg/Kg) and procyanidins (18-35 mg/Kg). Catechins (30-80 mg/Kg) prevail in the seeds.