Effect of leaf removal and ripening stage on the content of quercetin glycosides in Sangiovese grapes

Quercetin haze has been observed over the last few years in some aged Sangiovese wines. This problem could be due to an excess of quercetin wine. Leaf removal increases exposition clusters sunlight, which may enhance flavonol synthesis grapes. In this study, we evaluated dynamics related extractable flavonols grapes grown three usually defoliated Vitis vinifera (L.) cv. vineyards, whose wines showed precipitates. The particular structure vineyards leaf experiments were carried out allowed influence vineyard, biotype and rootstock on grape contents at mid-maturation technological maturity evaluated. leaves removed pre-flowering (early) veraison (late). increased content glycosidic two tested ripening stages. addition, affected interaction between studied variables was significant. Even though induced increase glycosides can risk wine, examination scientific literature topic that does not depend absolute these compounds alone.