The berry skin phenolic profile of Vitis vinifera L. (cv Barbera) as affected by time of bunch sunlight exposure

The relations existing among early and late bunch sunlight exposure, berry ripening and the anthocyanin and flavonol profiles were studied on cv. Barbera in 2005 in North-West Italy. Early bunch sunlight exposure extended the anthocyanin accumulation phase, decreased the esterified anthocyanin percentage and increased the quercetin-monoglucoside amount. On the contrary, the late bunch sunlight exposure reduced the accumulation of anthocyanins, induced an increase of malvidin-3-glucoside and total acylated compound percentages but it did not change the flavonol contents respect to the control. Besides, early and late bunch sunlight exposures diminished the anthocyanin extractability.