Polifenoli totali nelle bucce di uve rosse in vitigni calabresi

Polyphenols are among the mostimportant compounds in fruits. Theyare especially present in the pulp,seeds, and skin of fruits. Polyphenolcontent is strongly influenced bydegree of ripeness, temperature, light,and grape variety. In the presentpaper attention was focused on thetotal polyphenol content in berry skinduring grape ripening, from Augustto September, in the crop year 2009-2010. Four red grape varieties (Vitisvinifera L.) were investigated in thiswork, Alicante, Black Malvasia,Nerello and Prunesta, growing inthe Tyrrhenian side of the ReggioCalabria Province (South Italy).The Folin-Ciocalteu method wasapplied involving spectrophotometricUV-Visible analysis. Analysesshowed manifest differences in totalpolyphenol content among the fourvarieties. A typical trend with anincrease in quantity of the studiedantioxidant fraction until 16th ofSeptember and a decrease from 16thto 23rd of September, characterized allthe studied varieties.